bar risers?
 

I'm 5'11" @ 260 pounds. But I carry it all in my gut. My legs and arms are strong and thin (race tri's and full marathons).
I have 2006 Giant OCR1 with clip on aero bars. I can not ride in them or the drops for more then maybe 1/4 mile at a time. my gut gets in the way. I was thinking that maybe if I raised the bars 1/2 an inch it would make it better. Anyone know if this is something I can do? What would I need to do? I know jack about bikes if you can't tell.

java program to calculate stems...
http://alex.phred.org/stemchart/Default.aspx

the program will show you that even if you raise the current stem on the steer tube you'll shorten the overall reach a little also... so play with the program... and remember even just a few mm will make a HUGE difference... which is why getting the bike fit dialed in is so hard... the body can tollerate a lot... but when you get it dialed in it just clicks

I just bought a stem raiser from Harris Cyclery. I can't tell you how well it works though, because it has barely stopped raining here since I installed it. I like the idea of the raiser because now I can change stems without worrying about loading the headset. The raiser acts like a stem and keeps the headset tensioned.

If you aren't planning to install the stem or stem riser your self, you should ask this question at the shop where you plan to have the work done.