Everything Nate and Inkista said is correct. It depends on both your budget, and your needs. You can buy a normal sync cord to plug your flash into your camera for a little extra reach, or you can go cheap chinese wireless for a few dollars more and get real off-camera ability, or you can "go-pro" and spend hundreds or thousands of dollars more. There is a reason pros use the equipement that they do and spend many thousands of dollars on that equipment.
The whole point of getting the flash off camera is to get your light where it actually creates curves and contours, instead of red eyes and blindness. The farther your light source, typically the better.
My recommendation is to pick up cheap chinese (Cactus) wireless flash triggers, and a couple of decent silver/white reflectors. Play with them for a couple thousand shots, and then decide what you really need...also spend the next few dozen hours studying
Strobist before you buy anything at all.