A few comments in response to the posts about gearing:

There's nothing wrong with a triple, and a compact doesn't really cut it. I've ridden a compact a few times (34-50 teeth), and I didn't really like it because:
1. On the flat, there is no chainring to use when cruising. The 34 is definitely too small, and in the 50 I'm getting close to cross-chainring (big ring, big cog) whenever I find a slight incline. Sure, the 50 is OK on the flat, including the slight inclines when you're really going hard, but you don't always want to do that, sometimes you just wanna cruise and at those times, the 50 is too big and the 34 is too small to have a good amount of leeway in both directions (up-shifting and down-shifting) on the back.
2. On the downhills, the 50 tooth is not really big enough when I wanted to power down a straight downhill stretch, I missed my 52.
3. On the uphills, there are two things that I don't like about the 34. First, it doesn't give me a gear that I can sit and spin in when the gradient gets towards the double digits (i.e, >7%). I like to ride with a very high cadence, averaging 90+, and so the 34 doesn't work well for this on the steeps. The second thing about uphills is that for a more moderate or shorter climb, the 34 is too small. I was hammering up a moderate 4km long climb at the end of one of my favorite rides, some parts are somewhat steep (up to about 6%) so I definitely needed the small chainring, but some parts flatten off a bit and I really try to get some momentum going on those. However, when I did that I suddenly realized that I had run out of cogs on the back, I was in the small-small combo, and really needed to change into the big chainring. But making the change between the front chainrings, plus changing by a few cogs on the back would have taken far too much time and I would have lost all of the momentum that I was trying to build, so I didn't bother. A chainring in the 39-42 tooth range is absolutely perfect for that kind of climb.

Overall, I was very disappointed - I didn't like the gearing on the flat, the uphill, or the downhill. I agree, the compact looks better than the triple, and if you have a bike with a double already on it, then you can change to a compact without buying any new components other than the cransket. However, in terms of functionality, the triple wins hands down. It is said that a regular or compact double shifts better than a triple, but I'm not looking for super-slick shifting, I'm looking for a gear range that suits my riding style. Therefore, I would only recommend a triple to someone in Switzeland, or a standard doubles to people who live in flatter areas. I cannot imagine where a compact would be best.

Another word on the triple - the serious roadies will really start laughing at me for this one, but I don't care. I don't think the 30 tooth inner ring is small enough! I've now switched the 30 tooth chainring on all of my road bikes to 26 tooth rings, with the best combination then being a 26-39-52. Part of the reason for this is that with a 30 tooth ring, I would need a 12-27 cassette to get some good gears for serious (long and steep) climbs, but I don't like the spacing of the top three cogs on that: 21-24-27, the jumps are too big to keep a consistent cadence going and I'm often between gears. However, using a 26 tooth chainring means that I can use a 12-25 cassette, whose top three cogs only have 2 teeth between them: 21-23-25, which is much better spacing. My lowest gear is then 26-front-25-rear, which is significantly lower than a 30-front-27-rear, which is another advantage. A third advantage is that the 26 tooth cog and the 12-25 cassette are a few grams lighter than the 30 plus 12-27 combo. You won't be able to find a Shimano 26 tooth chainring anywhere, but other manufacturers like Stronglight make them* and you can easily get one from Veloplus. By doing this, you will exceed Shimano's stated capacity of the derailleurs, but you can easily get away with it - the rear derailleur has enough capacity to prevent the chain from contacting itself even if you do go into the small-small combo' (this applies to road rear derailleurs designed for triple chainrings, which Shimano likes to call the 'GS short' version) , and the front derailleur still shifts fine (obviously, you must have a front derailleur designed for a triple chainring). The stated derailleur capacities are always on the conservative side, it is usually possible to have a few more or less teeth than they say.

The moral of the story is not to let Shimano or other riders' opinions of style tell you what gears you should have - decide for yourself based on the riding that you do and the cadence that you like to ride at (which, to be more efficient, should be as high as is comfortable for you). I like riding up long, steep roads, at a high and consistent cadence, so a 26-39-52 plus 12-25 works perfectly for me.

On a related note, if like me, you don't like the cog spacing of Shimano's 12-27, but the 12-25 doesn't give you a low enough gear, then a great compromise is SRAM's 12-26, whose biggest three cogs are 21-23-26. It is designed to work perfectly with a Shimano drivetrain and I quite like that combination of sizes.

Sorry, Kate, this may all be too much for you at this point, you first need to worry about getting a good bike before worrying too much about customizing gearing combinations. However, much of what was said above sparked my lust to promote custom/non-standard gearing, and hopefully you'll benefit from my opinions on the compact vs triple debate.

BTW, I'll have a compact crankset for sale in a couple of months (once I've converted the last of our bikes) if anyone is interested.

* You don't need to worry about the non-Shimano 26 tooth chainring not matching the ramping pattern of your other Shimano chainrings because there are no ramps on small chainrings. However, you may need to put some thin washers between the 26-tooth cog and the attachment posts to match the Shimano spacing between the chainrings.