Any software that magniies circular region around the cursor?

[sri]

I am looking for a free s/w that will magnify a circular region around the cursor. Like in the screenshot below:



that screenshot is from a video and my guess is that it's a feature of some screencasting s/w on Mac.

I am on Windows and was wondering if such a feature is available in Camtasia or alternately if I can find any simple program that will magnify the region around the cursor.

Thanks for any pointers.

[jamiemac2005]

Same feature here:
http://www.imgpresents.com/magnify/mag.htm

Though i haven't yet found a freeware/OS alternative.

[PhilB66]

See Virtual Flashlight thread.

There are a few free s/w suggestions in that thread.

[PhilB66]

TunnelVision is another option.