For travelers and those with contacts in different time zones, the World Clock App is a pretty useful thing. It quickly converts the time between your favourite cities and time zones and you can set different alarms for them too, simply by selecting a city. Two bucks will get you there.
HD-retro graphics and other designs turn your iPhone into a nice alarm clock for your bed side table. Night Stand comes with high resolution skins for iPhone 4 and iPad. A simple weather forecast and multitasking included. Should have more that 8 skins though with its 1.99 price tag.