Online poker and taxes...?

[plomahaaaa]

I'm just curious how the government keeps track of gambling wins/losses over the internet. Someone told me that on partypoker the government looks at cashouts over $1500, which seems to make sense considering my large cashouts seem to take a bit longer. I tend to cashout/deposit a lot and have honestly lost track of my wins/losses...is this a big deal, something I need to be taking close tabs on? I am by no means a professional, more of a recreational player. It seems that it would be a bit of a hassle keeping track of all my sessions wins/losses, but at the same time I don't want to get myself in trouble with Uncle Sam. Also, typically what % of reported winnings go to the government?

Thanks