So the answer to your original question is that you'd need a 52 or 53 tooth chainring up front to replace the 50 (whether that's possible with your current crank is another story). In my own cycling experience, the only time I notice the difference between my bike with a compact (50 tooth) chainring and the other bike with a 52 tooth chainring is when I'm going down a substantial hill trying to keep up with somebody else. 30 + mph.
If that's what you're trying to work around, a new chainring might help you. If not, you have plenty of gears to ride at the speed you want to ride at with no equipment changes. IMHO.
You can go here and see what I mean - plug in your cassette and instead of the default for chainrings, use 50 for one and 53 for another and it will show you the speed differences for a given gear combo in a given cadence range.
Mike Sherman's Bicycle Gear Calculator
You can see that it's really not a very dramatic change at all. Ignore the low end, you would have shifted down to your middle chain-ring by then anyway.
