not that this has anything to do with anything, but i usually burn my ex's stuff. there's something symbolic and meaningful about destruction through fire... *sighs*
my two cents: hold onto the stuff. give her at least a couple weeks... i usually give ex's at least three weeks before i start talking to them again. if you guys can handle being friends again then she'll probably want the stuff back. you can either interpret her action as offensive or defensive... offensive in the sense that she's deliberately trying to hurt you by giving it to you. defensive in that she can't handle looking at things that remind her of you. note that she didn't destroy your stuff, that's got to mean something on some level. speaking from experience, give her space, let her choose the pace if you guys start getting close again, and if you're in doubt assume that it's over between you guys. that's generally what breaking up means to people. doesn't mean that things might not work out, it's just unhealthy to obsess about it. (put the box under your bed or similar)
anyways, sensitivity makes my brain disturbed so i'll end this by mentioning that when i see blog headlines like 'box', i immediately think 'rug', 'carpet', and other slang terms for a woman's genitalia. i think one of our subconsciouses is overly perverse... i blame you of course ;)