Hi,
I agree with the comments by JP and a few more touches I can see that would improve your site.
The dark backgrounds on the 'Find a xxx' image could/should be lightened up as the rest of the site has a bright clean feel about it but I found the almost black background very out of place with the rest of the format. A very light grey and those red, blue and green icons will still stand out and call for action.
Rather than being one image linking to the same 'Partners' default on the Join screen, consider making each icon separate images and linking to what the visitor is expecting to find.
Definitely too much happening on the front page, especially wasteful use of real estate is the Wall for example that needs to be scrolled before more interesting content is found.
You seem to be making the front page target new members and existing members and it sort of falls short on both accounts whereas I think it should be one or the other.
I would think given your objective is really about getting a large number of participants to join up that you should target the front page towards the casual visitor and getting them interested and registered. Give existing members a couple of quick portals or links to get through the community or social parts of the site that interest them or consider checking for a cookie and redirecting them to a different front page.
For a little bit of technical advice your <META> Description and Keywords needs to be updated. Description should be a a sentence(not more than 150 characters) that is like an elevator speech and uses keywords people are likely to use to find you and should be similar but not an exact copy of text the search engine might find in the body or early part of your page. For Example "Sports partners helps you find people and new friends to participate in activities, hobbies, clubs in your local area". Then in Keywords you use the same keywords and variations of them but don't go overboard.
Also consider using meaningful keywords in the 'Alt Text' areas of your images to help with Google and friends liking your site more
"Our Mission" actually isn't your mission but a description of of what the site is about, so probably just remove that title all together and put a bit more meat into what the site is about. You have about twenty seconds to engage the casual/new visitor to your site and tell them what you do and why they should join in a manner that interests them.
For a bit of Trivia, in a previous corporate life I worked for the second largest IT company, behind IBM(worked for them too at times), who for about six months had the mission statement of aiming to be Second Best!!! because they knew IBM was too far ahead to be the best. Bad mission statements wasn't their only problem, but I think people start to nod off when they read "Mission Statements" so keep your site copy friendly and corporate isn't friendly.
The Copyright needs to be fixed up.
Overall very good site and concept and I would have signed up but you only listed Wakeboarding and I am looking for Waterskiiers who might also wakeboard.
Terry
Feedback wanted / welcome 
