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. It makes easy to share your screencast on Twitter, YouTube or anywhere else on the web. Even iPhone users can view your screencast.
A smaller capture resolution means faster publishing and faster playback for your viewers. It also makes your recording sharper for viewers who don’t have as high a screen resolution as you do. The embedded player size uses the high-definition aspect ratio of 16:9. If you record with a 16:9 ratio, you won’t have black bars. So pick one of the preset HD sizes of 854×480 or 1280×720. You can also select one of these two presets and shift-drag the corner of the recording frame. This will lock the aspect ratio but allow you to select a resolution.