You can weight train daily is you switch out the muscle groups you're working each day. Jorge Cruise has a great workout plan that focuses on two opposing muscle groups per day, six days per week.
Monday: Chest, back
Tuesday: Shoulders, abs
Wednesday: Biceps, triceps
Thursday: Hamstrings, quads
Friday: Gluts, calves
Saturday: Inner and Outer thighs
If you want to you can double up Monday and Thursday on those days, Tuesday and Friday, and Wednesday and Saturday.
All you need to do is 4 sets of 12 at significant weight (reps 10-12 are difficult) on each muscle group with no rest between opposing groups and you're done in 8 or 16 mins.