Just got Yongnuo RF-603NII-N3 Wireless Flash Trigger Kit off Amazon for £31.
Does loads. Triggers SB-700 when off camera, in Manual mode only, admittedly, but TTL is like Russian Roulette to me anyway, never used it, never will. I prefer to set flash in manual and set flash output myself for consistency.
Yongnuo also triggers camera remotely too so two for the price of one, and only £31, and, unlike the Nikon, it's Radio controlled so don't have to be in line-of-site like with TV-remote style Nikon one.