i hear you james. currently, i am 135 and 6'1.25". i can only bench 140 and can curl 15 reps of a lousy 35 lbs. i want to build strength and mass to get a better physique and outlook. i was never conscious about my weight (or lack thereof) until hearing many comments about it too. i don't have a gym membership, but i want to start riding bikes some again to rebuild the "alexander hammer" legs i used to have when i raced bmx when i was younger... i just want to be stronger, and in the act, get bigger too...
i think a gym membership is good, especially if you are motivated. good luck dude.