Instead of posting student work on your walls or in the hallway, why not show it off to the world? Video and screencasting are great tools to record student work and embed it on a blog or wiki.

Videos

Youtube Still the best if unblocked. Never underestimate the intangible motivation for a student to post their work on YouTube.
Here is a tutorial to turn on comment moderation on YouTube. Thanks to Wesley Fryer.
Vimeo
Stupeflix
Ustream

Screencasting

Screencasting is recording whatever is on your computer screen with the option of audio with it. It is useful for creating tutorials and recording student projects that are not in an easily embeddable form. I also like to have students use it to create their own tutorials (see Mathcasts for an example) or solutions to challenge problemsfor assessment.

Jing Download required.
Screentoaster No download, but registration required.Embeddable.
Screen-o-matic No download, but registration required.Embeddable.
Screenjelly No download, but registration required.Can share of Twitter, e-mail, or Facebook. Embeddable.
Screenr No download, but registration required through Twitter account. Embeddable
ScreenCastle No download. No registration.Embeddable.
Screenpresso Download required.re-sizes images, scrolling feature, screenshots
Aviary download a button for your toolbar, register, great for screencapture that you can "mark up" and host online

Aviary is my new favorite for screencapture as it is easy and convenient. It has a whole suite of free tools worth exploring.