Hey Miguel,
Here is the site,
http://www.oneclicktennis.com/
You'll be able to sign up for free for probably the first year. You should register as a 3.5 or 3.75.
Let me know if you do the tournament. I'm thinking of doing it too.
Jim
hey! have you heard of gltf? ive been thinking of checking it out but i want someone to go with me, check it out online if youre interested too and let me know