Great suggestion Kate.
We picked up a pair the other week and have found them a very good (tough) work out. I still prefer my roller skis for general cross country training, but the fact that the skikes have a brake and go off-road, make them very versatile and much safer. Perfect for people who have not skied before.
Beware - you will get a very good, all body workout. Its not the same as cruising along on the roller blades. I guess that's why I like them.