Many sites have checkbox 'Remember me' in their login form which affects cookie lifetime (i.e. cookie lasts only for browser session or cookie will be expired in next several years). Perlmonks is not exception.

I think it is quite reasonable approach. I have this checkbox checked when I visit perlmonks from home and I don't check it when I visit perlmonks from other places.

--
Ilya Martynov (http://martynov.org/)