The last time I saw someone Busking it was outside a major league baseball stadium after a game. In fact I think I saw about 4 of them up and down a street that was between the stadium & affordable parking was at. Lots of people (thousands walking by) and many were willing to stop for a song & toss in a $1.
You might also check with craft shows, small county fairs, farmers markets, etc. You might have to rent a 'booth'. But if you start to draw a crowd then other people at the market might want to have you 'near them' for the spill over effect. I have seen this done at craft shows & farmer's markets here in the USA.
I suspect you need about 1 hours worth of music. Whatever you play you have to be able to nail it and draw folks in. If you can record yourself & make some CDs. You could sell them for $5 - $10. A friend of mine does this. Check out his 'extensive' library of songs at
http://www.soundclick.com/bands/page...?bandID=157137
He gets regular gigs at little bars & eateries to play from 5-8pm. He packs them in with his own style of blues & boggie.