goodtree, force for good? or scam?

[saladtossser]

http://www.goodtree.com/

looks like a good cause, you choose what you are interested in donating to, and you use their search engine (google, yahoo, msn, etc) and the clicks generate money that are donated to the things you care about

but then it had this "invite friends" thingy, and it asks you for your email and password. should people trust it? the password does need to be correct to work but could this be a phishing site?

[Flying_Salt]

You can use it, but you may want to scan your computer if it acts funny. NEVER give out your email/password.