I use a HOB
overflow box which drains down to my sump/fuge and then a pump returns the water back up to the main tank.
Pretty standard setup for tanks that aren't pre-drilled.
Here's a pic of one I found at another forum:
(I'd use a pic of my own but I'm on the road right now.)
*Edit: Crap, it didn't show up... Here's a link to the page:
Linky - Nano-reef.com Overflow box photo
You can either buy one at your LFS
or you can get them new/used all day long on ebay for pretty cheap like this one:
Linky - Used overflow box
Here's a full list of auctions and eBay stores selling overflow boxes:
Linky - Aquarium overflow boxes
If you want to buy one new, Drs Foster and Smith's website has some nice ones for under $100.
Linky - Doctors Foster and Smith continuous siphon overflow
You don't even need to get fancy with your 10gal fuge by adding baffles... you can just put your pump inside a piece of tall tupperware inside your 10gal to act as a baffle.
I'll try to post a pic of my own later.