Hi all, had my iPhone from day one (1st model, then 3G version).
Only real way to make ringtones in the UK is using Apple's Garageband music software (which is free when you buy a Mac, part of iLife suite).
Select your fav song, find the bit you like the most and trim to that selection.
Then you can export as a ringtone, works really well. You can do it other ways but this is the 'Official' way!
Now our US cousins of course can use iTunes to do this as songs available as ringtones can be edited directly in iTunes, we have been promised this but as usual we are way behind due to the complexity of copyright laws. BUT...
If you (and we do!) visit the US or have friends, buy a US iTunes voucher, get back home, change iTunes to the US store and you can redeem your voucher. It will ask you to set up a new account, but just set up a Googlemail account or similar (try not to use a co.uk), then you will have an account which will show a balance next to your sign in bar.
I have just bought my wife Enchanted for $9.99 and a movie for myself. I presume you could also buy songs that have ringtones assigned but not done that myself yet.
Applications:
well if you have Sky+, get the TV Plus app (better than the Sky official one)
eBay of course
Universal have one that tells you wait times on rides
Flashlight or MyLite
Bubblewrap
Flixster (movie times)
Sol Free
iPint
Dual Level
Labyrinth LE (Game, very good)
Lightsaber (may the force be with you!)
Lots more!!
Now, when you go to the US, unless you have Data Roaming switched on (and you shouldn't! unless you want a huge bill or have pre-paid for data from o2) you won't be able to use 3G, Wi-Fi is fine at Starbucks, McDonald's etc. This summer will be a huge software update which will hopefully address a few missing issues, one of them will be MMS messaging.