How to do integers to binary lists and back

[John Pote]

Hi everyone.
I recently had the problem of converting from an integer to its 
representation as a list of binary bits, each bit being an integer 1 or 
0, and vice versa. E.G.
0x53
becomes
[ 0, 1, 0, 1, 0, 0, 1, 1 ]

This I wanted to do for integers of many tens, if not hundreds, of bits. 
Python very nicely expands integers to any size required, great feature.

Just wondered if there was a neat way of doing this without resorting to 
a bit bashing loop.

Looking forward to some interesting answers,
John