had mine pierced back in '86 or '87. i've just turned 49, and over the years i've stretched them to a 00g. this is where i'm comfortable stopping the stretch, and i will end up installing some semi-permanent tunnels when i find the right length.
the best sensation i have found (for myself at least) is a metal tunnel with smaller guage rings going through the tunnels. the rings can swing freely, and create a VERY nice constant sensation when they swing freely.
body piercing isn't for everybody, but if you can get past the pain there is IMMENSE pleasure.