I just installed wordpress on localhost (a MacBook Pro Intel) and every time I try to login it just redirects me back to the login page.
Here's some version numbers:
mysql Ver 14.12 Distrib 5.0.41, for apple-darwin8.5.1 (i686) using readline 5.0
PHP Version 5.2.2
http://www.entropy.ch Release 1 (Universal Binary)