Kevin Federline KFEDERLINE030808_01.jpg Kevin Federline's certainly going to be Playing With Fire tonight - when he blows out the candles on his birthday cake!

The rapper turns the big 3-0 today. He's doing it in style, too - not only has his big birthday party been booked at Pure for months, but he'll be receiving a six-figure check from Caesar's Palace just for playing host!

That's a whole lotta money just for reminding the world you were born - maybe now he can start picking up the tab for his own legal bills?