Here are a couple of foot-fashion-related activities.

Designate a day as Knock Your Socks Off or Shoes Fly Don't Bother Me (I like bad puns).

Everyone is invited to come in either their most extravagant socks or footwear or both.
Those who participate (and participation is always optional) meet for a little potluck or coffee and a nosh. The footwear is shown off and ooh-ed and aah-ed over AND a picture is taken of the feet only.

The picture is then posted in staff room or some other place where only the library community can see it - an intranet would be good for this - and it is the challenge of the non-participants to match the feet with the people. The person who gets the most correct gets an appropriate prize - perhaps a recording of Nancy Sinatra's These Boots are Made for Walking? - and, if there is a generous knitter on your staff, a pair of hand-knitted socks. This is a cool way to have some fun and to show-off the arts & crafts talents of your staff.

This was tried in part at the University of the Pacific and a good time was had by all who participated.