Common or not? Sharing PS3 accounts with others

[pmac]

I was wondering if it is common place that people share PSN Store accounts. I mean I buy most decent even semi decent stuff (variety is the spice of life right?) and the Killzone 2 Demo is coming January 15th for Qore subscribers. I subscribe.

Do you trade accounts, do you share the expense with the primary trade games for access, or like what I wanted my girlfrinds to do when in highschool, just give it away.

I do not think this is a taboo subject because you can have up to 5 PS3's on your account. I was thinking that I want to work something out with maybe people that don't have credit cards and have it rough trying to get the online games.

Just wondering. Not sure how to put it out there. (Kinda just did but not really)

I would like opinions feedback thoughts etc.

Thanks