I buy quite a lot of stuff online, both on eBay and numerous online stores. The problem was that sometimes I lost track of which orders had arrived (on time or delayed) and which had seemed lost in the mail.

What I do now is right after each purchase I create a task like "WF e ipod" (WF = waiting for, e = eBay, ipod = iPod); if necessary, I add the order number. I set the due time a few days after the expected delivery time.

If the item doesn't arrive on time I follow up with the seller and/or try to locate the package using any tracking info provided.