Screenr

Screenr is a web-based tool that lets you create screencasts without installing any software. You just click the record button and your screen activity is recorded along with narration from your microphone. Screenr then publishes your screencast in high-definition Flash format. Screenr makes it easy to share your screencast on Twitter, YouTube or anywhere else on the web. Even iPhone users can view your screencast.

Features:

• Nothing to download or record.
• Record on your Mac or PC.
• Play everywhere even on your mobile phones.
• Completely free of cost.
• keyboard shortcuts for screen recording
• HD recording
• Most Common browsers are supported, including IE 6, 7,  and firefox 3.0+, Safari 3 + and Google Chrome.