Newbie: where's the new python gone?

[BobAalsma]

I think I've installed Python 2.7.3 according to the instructions in the README, and now want to use that version. 
However, when typing "python" in Terminal, I get "Python 2.6.4 (r264:75821M, Oct 27 2009, 19:48:32) ".
So:
(1) I can't seem to find where the new software has gone and 
(2) can't seem to find how to point to this new versoin.
I've searched Python.org and with Google but :(
[I'm on Mac OS X 10.7.4]

Please help.