Smith Street in Collingwood (I think!) is pretty good for Factory Outlet shopping. It's a lot like Harbour Town, except it's all on one big long street and specialises in having HEAPS of outlets for sports gear like Adidas and Nike. I'm a big fan of the Adidas one, every time I've been there I've always picked up brand new retail samples that never make the shelves here! You can catch the Number 86 tram out to Smith St, and it only takes about 10 minutes to get there!
The Queen Victoria Markets are the main markets in Melbourne. Easy as to get there, just take any tram straight up north from Elizabeth Street in the city. There's the usual produce side (aka, THE SMELLY BIT!), and then the "general random crap" side which is fun to explore...although all I bought last time I went there was a 1kg sack of lollies and a really dodgy denim jacket for $10. It's pretty huge, and good for random crap.
God, I feel like that Postcards guy...except doing the grand tour of Melbourne! I can't help it, I love Melbourne. If there was one other city in Australia where I'd love to live more than Adelaide, it's Melbourne...or maybe Brisbane...it's sunny there.