Originally Posted by
sstorkel
... a speed of 30mph. That's a pretty decent speed for anything except a sprint race...
... or going down a hill - but that doesn't seem likely
Make no mistake - 42/13 with a 26" wheel is a very small top gear.
To the OP - the GT bike you mentioned is a good one, and there are many many others. The model/brand/components are actually much less important than the fit of the bike - you need to be comfortable riding it.
The Specialized bike you have is set up to have a lower top gear than just about any other hybrid or comfort bike out there. But a bike with narrower high er pressure tires will roll much easier and you will likely be noticably faster as soon as you swap. Just pay attention to what gears come stock on your new bike, and check it all out using
sheldon brown's gear calculator...
Also, please keep in mind the comments made here about keeping your cadence high... spinning your legs at a higher rpm is easier on your body and gives a better aerobic workout than mashing at a slow cadence - although it sounds like you are keeping your feet moving pretty fast already.
Good luck!