Unfortunately players in different regions will not be able to interact with each other in any way. This includes:
- Playing games together
- Viewing profiles
- Adding them to friends list
- Any form of in game chat.
Currently (the end of Season 1) - the only option you have is to start a new account in the same region as your friend.
There is no way to transfer your account from one region to another. This may change in the future†, however I'd imagine that it would incur a charge in the form of Riot Points.
If you decide to create a new account, bare in mind that playing in the wrong region could also give you in game latency issues, which will have a negative impact on your gaming experience, depending on the level of the problem.
†
http://www.leagueoflegends.com/board/showthread.php?t=165067&page=7
Jesse Perring
Customer Support Specialist
09-13-2010, 11:40 AM All of the
feedback is always greatly
appreciated. We are definitely paying
attention. Unfortunately, right now
it's just not possible from a
technical standpoint to transfer any
account content, between two servers,
or even on one server. It's something
we're thinking about for the future,
but we can't be sure if or when it
will be available yet.