I honestly wouldn't even recommend that program...The quality of your images if completely shot when you save it as GIF. That's why I am requesting that someone with another program animate 2 certain images.
I can give you a couple simple pointers that would really improve your sigs...which are pretty damn good as they are.
But yeah, I'll get that request done soon.
Those really look great, but I'd suggest getting rid of the white inner portions of the logos...Particularly in the 1st one...plus, you might want to consider using the official walking bear logo that you can easily find in a good size on Google.
You can always lower its opacity or mess around with the Blending Options (glow, bevel/emboss)...or go with a different font altogether. Lately I've really liked BankGothic and used it within most of my sigs. Give it a try:
http://www.typenow.net/files/B/bank_gothic.zip
Or try enhancing the Oswalt photo by adding some Brightness/Contrast or Saturation effects to it.