Source for flexible, stranded wire
For how little of it I use, I usually just run to Radio Shack and pick up whatever stranded wire they have in the electronic component section.  If you're in the U.S., that should be sufficient.  By the time you pay shipping, you're not saving any money getting it from Mouser, and if you're not using it in large quantities there's no bulk pricing advantage.

The other thing you can do is look for other types of wire.  I've used speaker wire in a pinch for things like power.  You can usually find pretty thin, stranded speaker wire at most general-goods retailers (Wal-Mart, for example) or electronics specialty retailers.  As long as it's just for power, it should be quite sufficient.  Again, it probably won't be any more expensive and will save you time to go pick this up at the store rather than order it from Mouser.

If you just want a few feet, I'd be tempted to hit up my local hardware store.  They usually have stranded wire by the foot.  You might have to settle for something of a slightly larger size, but my local Home Depot and Lowe's (again, U.S. stores) have 22-ga stranded wire available by the foot.

Direct from Mouser, well, there's a whole ton of options.  The following link will show you all 22-ga hook-up wire options on 100' spools that Mouser sells.  There are 205 results returned, they should in large part be sufficient for your needs, and start at $20.  You'll excuse me if I don't go through each one individually:
http://www.mouser.com/Wire-Cable/Wire-Single-Conductor/_/N-5ggs?P=1z0jnerZ1z0juksZ1z0wxmfZ1yzvwzvZ1z0xg0i

If there are smaller spools available, I missed them.  Also, you could easily use other wire  gauges as well (20, for example).

FWIW, I have taken solid-core wire and wound it "backwards" around a spool to remove the curves, and other objects can be used to give it other shapes (as well as simply pinching).  I find that 22ga wire can be bent to pretty much any shape I want this way, if that helps.