I just found a new book series which I gather will be pretty MacGyver-like.

The series is called "Mission: Survival" and is a kids (9-11) adventure series written by Bear Grylls!
Each book is a separate adventure, but they are all based around a character called Beck Granger, who, like MacGyver, finds himself in situations where he must use his extensive survival knowledge and know-how to save himself and his companions. The lead character is only a teenager I think, so these stories could well be like a Young MacGyver series might be.
The kewl think is that Beck Granger actually uses the real survival techniques we see Bear using in Man vs Wild as well has a bunch of other hints on how to survive, so not only do you get an exciting adventure, but you learn real survival information along the way.
I'm not much of a reader, but I'm thinking from all the rave reviews these books are getting, these might be a good read for my kids, since they are both pretty into Man vs Wild/out door adventure type stuff
Here's the official web site for the series which includes excerpts from the books so you can get a feel for them.

And here's an indication of price in both the U.S. and the U.K.