One of the most useful gadget-type thingamajiggies I've ever used is this set of mini-extension cords from Herrington's catalog:
http://herrington-catalog.stores.yahoo.net/t187.html
They're called Pass-Through Liberation cords, and I have bought dozens.
They're especially handy at craft shows, when you have several gadgets that require a transformer. I have case lights with transformers, and two took up an entire surge strip. Now one surge strip handles them all.
In my home and studio, same thing. We have multiple business lines with cordless phones, a fax, a credit card terminal, a home line with multiple cordless phones, electric bead reamers, cordless doorbells--the number of transformers is ridiculous. Fortunately, these mini-extension cords helps keep the number of surge strips down.
No affiliation with the catalog or manufacturer, just a happy, happy customer.