Well the scanning takes as long as the scanning takes. Not much can be done about that. Of course if you already have the scan and are just relisting, or listing a similar auction then its done one time only. There are some things that you can do to lessen the time it takes to post an auction though.

Depending on the computer type you are using there may be software that you can create templates offline and load them into ebay automagically. For example, if you are a Mac user, like I have become recently, there is an application called GarageSale that will help you post and monitor all your auctions. There are equivalent programs for the PC to help out as well.

Ebay also provides an easy way to sell a similar product through links on their site from your auction. So when the auction finishes you can essentially sell a 2nd of the ame chip (if it makes sense) or change the auction slightly as needed.