With the new store feature that allows you to have users sell items, I figured I'd drop this little hint...
If you want to restrict what people can or can't do when posting something for sale, like when you don't want people being able to set shipping, etc. just do this:
1.) Find the "additem" function in Store2.php
2.) Place style="display:none;" within the <tr> tag of any option you want to disappear! They're named pretty clearly in the code, so you'll be able to spot which lines of code relate to which options.
It's that simple.