October 30th.
You can't find mew without an event. Sorry.
Mewtwo is in cerulean cave, and you can only get Mew through an event.
Nintendo event or action replay
You don't. Just go and get it at an event.
act fast and get him on wifi event
What do you mean what does it do? Its a mew, a free mew lvl 5 to do what you want with, it does not trigger any events
You get him in trade with a friend or you do the event that past already.
There was a Mew Wi-Fi event in Japan, but there is no sign of there being one anymore as of December 18, 2010.
You get it from a Pokemon Event that has ended.
...or is someone willing to give me one for free?
You can't, you must trade from Emerald (which had an event to get to Mew), or trade from Pokemon Ranch (if you unlocked it).
Mew is not in in Pokemon SoulSilver. There was a Mew event however that has ended on February the 11th. You can still catch a Mewtwo in Cerulean Cave at level 70.