I really, really don't like gloves in the summertime, so I solved my
numb finger and hand pain problem by padding my dropped bars under the
bar wrap. I use Marsas Bar Pads from wallbike.com underneach Profile
Designs bar wrap. It makes my bars much thicker and they fit the palms
of my hands much better with a bit of cushion.
My theory is that the standard wrapped handlbar is narrow enough to fit
between the pads of flesh below your thumb and at the heel of your
hand. There seems to be a nerve or some in there that get squished and
make parts of your hand unhappy as a result. My hands fit more
comfortably around my padded bars and I no longer suffer from finger
numbness or pain.
I'm sure there are many sources of high quality padding you could use
on your bars. I got mine here:
http://www.wallbike.com/oddsnends/marsas.html