I'd say make a Twister or even a Chubby Charmer bag by Quilts Illustrated.

I am currently using a charm pack that is all florals to make a pinwheel quilt. I am using the easy pinwheel construction that I saw (I think) on Eleanor Burns website. You place two squares face to face and sew around all 4 sides 1/4" inside. Then you cut from one diagonal to the other (top to bottom), then diagonally side to side. Open up the 4 pieces, trim the dogs ears and sew together for a very fast pinwheel. It's so fast and easy, especially if you are starting with square precuts -- doesn't matter what size.
cheers

Quiltnmore, I really like that pattern and it looks like a really quick and easy pattern to put together when you need something quickly. I also have a bunch of charm packs that I have picked up but have not used them. This is a really good idea, Thanks for sharing it with us.
Pat

Fabric companies have many free projects on their websites which showcase specific cuts of fabrics. Here are just a few that I've used for inspiration

http://www.modabakeshop.com/
http://www.ttfabrics.net/patterns/
http://www.windhamfabrics.com/projects/

I vote for the twister - it's pretty addictive.

Disappearing nine patch is another good one. Or gift them to me :)

The fabric is Moda's Bliss line, by Bonnie and Camille... No patterns, just did my own thing.

I just made a table topper from 2 charm packs that I have had for some time. I used one of the Schnibbles patterns and it turned out perfect, no left overs. You should try one of their patterns.

I like to make placemats with them. I pick out an additional coordinating fabric from my stash, but a few 5" squares from that, and use the resting for napkins. Works up cute! I can get 4 placemats from a collection of 5" squares by doing it this way.

I'm currently using some charm packs for a Grandmothers Flower Garden. Cutting them into 4ths makes 4 perfect size (1") hexies. I'm using several though since I want at least a generous lap quilt!