Circuit City is merging their online site with their retail stores with a pretty good idea.

Let your customer shop and order online, and then pick up item(s) in 24 minutes at your retail store.
Pros:
Online price comparison before buying.
Save on shipping costs.
Verify item is in stock.
Save time by not standing in checkout line.
Pick up item in time for holidays.
Cons:
Are taxes charged because item is picked up at retailer versus online?
Inventory requirements would have to be higher.
Big items (TVs) could be a hassle to transport...a possibility to sell shipping service at store?
What would I do if I was in charge of their mobile marketing?
Include a n option where customer could provide their mobile number. The store would send a text as soon as item is ready. For using this service I would resend (with their permission) a 2d bar code/coupon to be used the NEXT TIME they visit the store.