I do this all the time. In fact, unless I fly internationally, I never check a bag. I use the same carry-on bag for every flight, and it just depends on the size of the plane if I have to gate check it or not. When the charge to check your first bag started, I switched to carry-on because I didn't see the reason why I should pay $25 to ship my full bottles of shampoo or extra items, etc.... It also helped me really prioritize what I need to pack and what I just want to pack.
I have noticed, though, that because I am a frequent flyer on United, I am usually in one of the early zones (2 or 3) so I usually don't have to gate check the bag. However, when I fly US Airways, I always have to gate check because I'm way back in zone 4 or 5. Which brings up another question, does anyone else understand the way airplanes board? I've never been able to figure it out, because you would think that the earlier zones have the window seats and then they move outward. Not true. I can't tell you have many times I've been in the later zones and have had a window seat.