Conventional wisdom for adults is to get the most aperture for the $, such as an 8" reflector, but I don't think this always translates well to a kid.

Here's a good question for the parent/kid: if they were talking about a bicycle, is this the kind of kid who wants to just get a bike so they can ride and have fun, or are they the kid that wants to change their own tubes, take the bike apart, overhaul the hubs, etc? If it's the latter, then yeah, maybe an 8" dob. But that is a rare kid. I think most kids are better served by something fun and accessible, not a chore.

If that's the case, I'd go with a small refractor or mak-cass on a good alt-az mount. That way the kid can spend more time observing and learning than messing around with collimation and cooling.

That Orion Go-scope linked by tphelan is a good call.

Consider something like this, which has a Celestron SkyScout included which is a nice educational aid. http://www.optcorp.com/product.aspx?pid=10581

If you want to push the budget, this is a nice looking scope, but I can't vouch for it personally. I do have the same mount and it is rock solid, good enough for adult use. http://www.amazon.com/Vixen-39952-A80Mf-Telescope-Porta/dp/B0027VSSUE