Well, with a friend we tried the Hamachi software with very bad results (he and me live in Spain) the lag was of about 5 minutes
Later, we tried creating a VPN with a lag of about 0,5 - 1 sec with connections of: 512dw/128up and mine: 2mb dw/300up I was the host and the results was bad.
Here is another utility but my english is bad and we tried to run it but there was no-connection betwen he and me.
http://www.morpheussoftware.net/git/
The program is "GIT" gamer's internet tunnel
It's a VPN without security systems so it is the best solution I think.
Sorry for my english