kettlebells are lots of fun, and BELIEVE ME, there harder than dumbells and barbells, they will really give you much more of a cardiovascular workout than dumbells and barbells.
I got my father one for "father's day" he was never into anytype of training at all, especailly cardio stuff, I showed him how to do the basic "two-hand swing" with them, he said he loves it, and my mother wants a kettlebell now.
my buddy Graham, a 47year old strongman with bad shoulders got some also, and he says he's got much more respect for 50lbs now, plus it's helping his shoulders out, Graham's wife is also working out with them, and so is my training partners wife.
my
training partner and I do lots of lifts using them, one-arm snatches,swings, you can do front squats,overhead squats, juggle them, the list goes on and on, great for the core.