OMG, can you people please visit those three websites? I've tried it and it works.

Take your cell phone and fire up your symbian browser and go to free.talkster.com. Get your Talkster number for your friend and let your friend do the same for your. Now call your friend with that Talkster number you just received and when he answers he should hang up but not you, then he calls you back on his Talkster number for you (while you're on hold) and you talk for unlimited period of time.

You can also do that over your PC and you can also have group chats.