Random note:
Lots of people searching for a From-Fillable character sheet also expect to be able to save their information in the sheet once it's entered.
Most form-fillable sheets don't do that, unless you've got the full version of Adobe Acrobat.
If you happen to be on a Windows based machine, you can use FoxIt PDF viewer to handle this. With a slight caveat.
Certain sheets (Mad Irishman's for example) use layers in order to show/hide elements. FoxIt can't handle this. It'll either not display the information at all (some e-tiles use adobe layers) or it'll just cram it all onto the dispaly (mad irishman's sheets).
In theory, FoxIt is working on a Mac version. I wouldn't hold my breath though, they've been working on it for quite some time.
I happen to currently be using an Ubuntu machine and the Linux version they have doesn't work on my box either.
But for you Windows useres... knock yourself out. Besides being able to save pdfs that you've filled information in, it just makes for a kick-ass pdf viewer in general. On my windows machine, I use it for 90% of my stuff.
Foxit Software - Foxit Reader 3.0 for Windows