Sessions or Cookies?

Hi all, I'm about to create a site where visitors will be able to search, view, surf and add items to a shopping cart without logging in to the site, but will need to do that in order to complete the transaction of course. What I wonder, is what to use to collect information about the items the visitor has chosen in order to show them in the cart section... Should I use the no-so-secure old cookies method or should I start a new session every time a client drops in and handle each cart by session name or ID? Of course I would rather store every visitor's temporary cart in a long MySQL DB and not in their Hard Disks because of those 4 Kb of limit cookies have. Any suggestions? Thanks in advance, Cesar L. Aracena icaam@icaam.com.ar caracena@infovia.com.ar (0299) 156-356688 Neuquén (8300) Capital Argentina