Most popular social networking websites in Berlin

Hi there I'm looking for someone coz I lost their email address and I was wondering what social networking site do most Berliners use?

how old? studivz if under 30, or xing (any age up to 50 or so) are the most common.

Do they work, can you contact them there?

no I dont know too much about them it was a very late/early exchange!!! how do you find someone with just a first name, near on impossible

Check out www.lokalisten.de as well.

so annoying I cant navigate around them to do a search

you cant do a search without joining those sites or am I wrong?

Maybe try placing an ad in Zitty or TIP? I'm pretty sure they have a "missed connections" type of section.
Or if they're not German, maybe try an ad in the Exberliner?

couchsurfing.com if they wern't German