One idea is to pack a bunch of emergcy flat tools into a water bottle, like this:
http://www.outdoordivas.com/outdoord...AIAOGHJDIAIDJ&
I'm sure you could do it cheaper yourself. Here's a guy who does it too:
http://members.tripod.com/derek_fitz...e/trilist.html
Of course, then you'll need two bottle cages- one for actual water!

Personally, I find it too annoying and uncomfortable to carry extra lumpy stuff on my body when riding. Most small wedge shaped saddle bags won't touch your thighs at all.