HD Video isn't just coming to every television screen, it's making its way online as well. From well known video sites like YouTube to unknown upstarts like Vuze, many online video services are embracing the new standard.

Here's a list of 20 great sources where you can find High Definition videos. Making the switch is easy; the only thing that's blurred is the line between online and offline entertainment.

Tell us more about where you find HD videos in the comments.

Online HD Video Streaming

Apple - The Mac daddy site sports an excellent HD Video section with plenty of movie trailers, music videos and more. For the best experience, you'll need to install/upgrade your QuickTime player.

Microsoft - Not to be outdone yet again by Apple, the boys from Redmond have added support for HD Video to their Windows Media player. Their WMV HD showcase has plenty of IMAX clips in HD as well as some movie trailers.

SmoothHD - This is a joint effort from Microsoft and Akamai for delivering HD content over HTTP with the help of SilverLight as part of the Open Video Player initiative.

Hulu - The hot video service has an extensive HD gallery of movies to behold. There are full-length feature films you can experience in HD for free. For example, here's a trailer for Quantum of Solice.

Vimeo - Now supports HD in 1280x780 and lets you upload videos and convert them to HD.

Adobe - Has jumped into the HD Video arena as well by adding HD support to their Flash player technology. Here's their HD Gallery.

Vuze - Provides a downloadable player that lets you view stunning HD Video content. The site is reminiscent of Hulu and YouTube with its search capabilities.

DailyMotion - The French video service supports the HD format.

YouTube - Well, there isn't any special area for YouTube HD Video content because it only plays high quality video if it's available and if you have a fast Internet connection. If you want to force YouTube to always play the high quality video whenever it's available, change your option under account setting to do so:

MotionBox - Allows you to upload your home movies and convert them to HD Video. Go here for more information on the service.

NASA - If you're into HD space exploration then this is the place to go. Many blasts from the past.

NY Times - The popular newspaper has recently launched an HD Video Portal based on Brightcove's player.

Broadcast TV Channels in HD

CBS - Maintains a wide selection of HD Videos you can watch in their entirety, such as CSI: NY, The Amazing Race and many more.

ABC - Follows suit with their rival by streaming many of their shows online in HD. Requires you to install a small movie plugin for your browser.

NBC - NBC also streams their shows online in HD. Keep in mind that not all of their video content is in HD format. Look for the HD symbol next to the show name to verify. Also, you can download many shows in HD from their NBC Direct service for free.

HD TV Resources

Boxee.TV - Software that lets you connect video sites to your HDTV so you can enjoy HD video on your big screen. For example, you can stream hulu.com to your AppleTV.

vudu - Set-top Box that allows you to watch a slew of HD and HDX video instantly from an online selection.

AppleTV - Apple also provides a set-top box that lets you play HD movies, TV Shows and more.

XBox 360 - Microsoft has a set-top box that plays HD Video content such as movies and TV shows. You can find plenty of HD content at their xBox Live Marketplace.

Tivo HD - The new line of Tivo boxes support HD and Internet access, which means you can stream HD video from online services such as YouTube and NetFlix. You can also share your HD converted home movies with friends and family members.

Image courtesy of iStockPhoto, Bim