04 Nov 2008 02 Jan 2009
To add to JLogan27, make sure the 'piggy banks' in the level and the 'fire hydrants' are SHOT. The piggy banks give you MUCH more when collecting the coins that come out of them rather than collecting the pig itself. Shields in fire hydrants are also valuable.
I was getting 20-23k a go (5-6 minutes) so you can imagine how much easier it is to get 1million that way.
UPDATE: The Level you want to be repeating is Level 5.