I just noticed that the guy behind InstaCalc recently released a Vista Sidebar gadget. All the other calculator gadgets I’ve seen are horrible with a terrible UI and often requires me to explicitly use a mouse to enter in my calculations.

The Instacalc gadget is neat because answers are computed on the fly after every keypress.  Just like it’s bigger brother website, it supports variable assignment (”x=5; y=4; x+y”)and easy use of units and conversions. (”1GB + 4MB” gives me 1,077,936,128).

So far the only area of improvement is somehow allow hotkey activation, but I don’t think the Sidebar framework allows gadgets to do that, so I can’t fault the author for that.  I’m shocked this gadget is only rated at 2.5 out of 5 stars.