For me, yesterday’s most exciting announcement was the release of Safari 5. If you haven’t yet downloaded it, you can get it by going to Software Update in the Apple menu, or by downloading it from the Apple site. It has a whole load of great new features like Reader and Extensions, and we get our nice blue loading bar back and animated GIFs actually load in less than an hour.

Arguably one of the best new features is the support for Extensions. If you’ve ever used Firefox or Chrome you might be familiar with these. While the Safari Extensions gallery isn’t opening until “later this summer,” it is possible to enable Extensions right away.

To do this, first go to Preferences in the Safari menu. In the Advanced section, click the checkbox at the bottom to enable the Develop menu. Go to this menu (it should just appear in the menubar) and the select third item in the list, “Enable Extensions.” Now, when you go back to the preferences there is a new Extensions section. Considering the complexity of this process, I’m sure it won’t be long before Extensions are enabled by default.

So now Extensions are enabled, where can you get them from?

Well, before Safari 5 was even available, Panic managed to announce their Coda Notes extension. It looks great, but unfortunately it’s still “Coming Soon.” Almost as quick was John Siracusa, who has posted a simple extension on his Twitter feed that you can actually download. All it does is add a Reload button to the toolbar, something that many people have been asking for since it moved into the address bar in Safari 4. After you download the file, just double-click on it and it will be installed. It will actually be deleted from your downloads folder after it is installed, so don’t get confused when it disappears. Note that the button won’t be added to the toolbar automatically, you have to go to the View menu and choose “Customize Toolbar” to add it.

There are a whole load of other Extensions listed at this page. Currently there are things like a Gmail unread messages checker and an Amazon search bar, and it looks like new ones will be added as they are released. It is probably worth noting that as far as I know these haven’t been screened by Apple, so there might be an element of risk in downloading them. As always, you should only really download things from sources that you trust, so if you want to be really safe you might want to wait until the official Apple Extension Gallery is live.

[Update: There’s another great list of extensions over at reddit]

Once each Extension is installed, it should show up in the Extensions section of the preferences. From here you can enable and disable all Extensions, turn on automatic updates and uninstall any Extensions that you no longer want.