Best php 5 session alternative to Native Session

[eluser]obobo[/eluser]
I've been using the Native Session library on previous projects running php 4, but i'm upgrading to php 5 now and need to have sessions expire when the browser is closed. I'd also like to start storing sessions in my db, but that is currently less of a priority than the browser close issue.

What is the best current alternative to Native Session library for php 5?

I found KNDB, but there was some discussion as to whether its method of storing variables in cookies was secure. I'm a complete novice on that front, so have no way of determining for myself.

any suggestions?