I'm currently using silverstripe's built in member management functions to log users in and out so that they can see various areas of front-end templates available to logged-in users only.

I also need to store additional data for logged in members in a session (wishlist/cart items). Is there a member-specific session that I can use/add to that will be automatically destroyed on logout?

Alternatively, what other ways can I do this?

You can use the Session class to store values tied to a session. Another less secure / robust way is using cookies.

Session::set('MyValue', 2);
Session::get('MyValue');

http://api.silverstripe.org/2.4/sapphire/control/Session.html
http://api.silverstripe.org/2.4/sapphire/misc/Cookie.html

Thanks Willr.
Could you give me a specific example of how I could tie a value in with the member session -- sorry, haven't worked much with sessions in SS.

Ask and you shall receive! I've done up a documentation page explaining it and examples on how to use it.

http://doc.silverstripe.org/sessions

Awesome - thanks!!