It has now been 500 days since my iPad 3G arrived at the end of April, 2010. So, as I did after 100 days — when it was my “favorite” computer — and after 300 days — when I barely used it anymore — I’m going to write a bit about how it fits into my life today and what that means.

After almost a year and a half with the iPad, I now consider my usage at “normal everyday” levels. That is, I use my iPad more than I did earlier this year — after I wrote that I was bored with it, and tried forcing myself to use it more — but less than when I first got it and took it everywhere with me.

Specifically, I use the iPad for about 30 to 60 minutes per day, almost entirely at home.

At home, about 75% of the time I spend on the iPad is in the Safari browser, reading a few aviation websites for fun before I fall asleep every night. I have a lot of apps — dozens — but I generally don’t use them often, or for very much time.

Of the apps I use frequently, I mostly check Twitter and the App Store, and watch a few minutes of TV using the Time Warner Cable app, which is an awesome concept but is as well-designed as you would expect from a cable company.

I spent the month of July watching NBC’s Tour de France live streaming TV coverage on the iPad for a few hours a day, and it was great. There were some technical/design issues to conquer, but in general, it was better than watching on TV, and easily worth the $15.

I still really want to use Facebook but it doesn’t exist yet. The web versions aren’t good enough, and the fake Facebook apps are lame. I’m pretty disappointed with Facebook’s mobile stuff lately — they need to get their act together.

I have downloaded a few magazine apps (Bloomberg Businessweek, New York, Esquire) but barely use them. The wait time to download a new issue is still so long that by the time it’s downloaded, I’m already thinking about something else. (My favorite part is the video in the Businessweek app about how they designed the cover. That’s often all I consume from each issue, despite paying for a monthly subscription.) I am generally disappointed by the ads in these apps.

I haven’t read an e-book in months, and haven’t finished one in about a year.

I rarely use Flipboard or Instapaper anymore. I tried the AOL Editions app, which looks nice, but it’s not for me. (I spend all day on Twitter and Facebook, so I’m pretty plugged in to the news.) I need to fly to Japan again, or something, so I can read my whole Instapaper backlog.

I haven’t played an iPad game in months. It’s too heavy to hold up for very long, which makes many games tedious. Are there even any great iPad games?

I don’t have an Apple TV — old TV, no HDMI port, old Mac mini hooked up via DVI — so I don’t use AirPlay. But I’m intrigued by it.

I really want to buy one of these iProp iPad swing-arm holders for reading and watching video in bed. I will let you know if I do. It looks like a neat tool.

I also use the iPad on longer trips. In my new life as an independent publisher, working mostly from home, I’ve removed a 45-minute, twice-daily commute out of the equation. (And I never felt comfortable using my iPad on the subway, anyway.) But whenever I have a few hours on a train or airplane, I find myself watching video on the iPad.

On a recent trip out of town, it was very cool to be able to stream a college football game live via the ESPN app while waiting to check in to my hotel. The iPad is also a much better device for airplane wifi than a laptop, because you can actually use it comfortably in an economy-class seat. (And you never have to worry about charging it or weird power adapters, because the battery is so amazing, even 500 days later.)

I got rid of my iPad 3G data plan. I had kept it for more than a year, billing $30 every month, to stay grandfathered into AT&T’s unlimited data plan. But whenever I tried to use it — to stream video at the gym, or something — the service was so bad that it didn’t work, anyway. I couldn’t use more than 2 GB a month if I tried. Instead, I’ve signed up for iPhone tethering. It’s the same flaky AT&T data service, but I can use it with my iPad or any device.

My MacBook Air remains my go-to portable computer. This is a big reason I don’t use my iPad as much as I did at the beginning, or even as much as I’d like to. For the work I do — switching between two dozen Chrome tabs, writing in one and reading from another side-by-side, saving huge photos and editing them, constantly checking email and Twitter — the iPad doesn’t cut it. But I realize that most people are less-insane computer users, and will get much more mileage out of their iPads. The iPad 2 users at Starbucks seem genuinely happy. I am glad to have both the iPad and MacBook Air, but I generally choose the Air for everything but reading in bed or watching videos.

I am excited for iOS 5 and the iPad 3. I hope iOS 5’s Newsstand feature makes downloading magazines less agonizing. (On the other hand, I also hope iOS 5 doesn’t make my iPad unbearably slow.) I hope iCloud can make managing all my stuff easier. I will probably upgrade to an iPad 3 when it comes out (wi-fi only, 32 GB), if it has a retina display. That’s why I didn’t get an iPad 2 — the screen resolution is the biggest upgrade I’m looking for. I will continue to invest in future iPads, and hope that someday I can do everything with a touch-based device.

I still think the iPad is the future of computing. It is a great consumer device, and it has a bunch of interesting “enterprise” uses, too. I will check out Amazon’s tablet when it comes out, but nothing else out there excites me. I couldn’t even justify buying a $99 HP TouchPad as a gag. Apple still has a lock on the tablet story, with unparalleled hardware, software, apps, and content.

I think the biggest thing that’s still missing is great third-party iPad software. It is much harder to make a great iPad app than a great iPhone app, and Apple itself still seems to be doing the best work. (iWork, iMovie, GarageBand, etc.) But it is still insanely early in the tablet business. As the user base expands and as developers get more creative, the next few years should be really cool.

Also: 10 new industries Apple could go into (but probably won’t)