This thread pops up every once in awhile.
Some "blast from the past" ideas:
- Foam bicycle handlebar pads -- can be hard to slip on, but HUBBA, HUBBA!! Cushy and warm when it's cold out, or stays cooler when it's hot.
- Friction tape -- cheap, works great, with a sticky grip, but has a smell to it.
- Adhesive ('cause there are non-adhesive versions that don't work as well) racquet or bike handle tape.
- the ever popular old inner tube trick, as stated above.
- as for the medical adhesive tape mentioned before, if you look for it, it comes in quite a few colors.