All exercises can have "usefulness." Even curls (which take a beating around here) CAN be useful. For example, in wrestling isolated arm movement is often used. So, some wrestling strength programs include curls believe it or not. However, as a general rule for body building the basics rule the day.
These exercises I queston the utility of with the above caveat of course. I'm sure there is somebody somewhere that can justify these:
1. Pullovers--suck for the most part and strain the elbows if you use dumbells--this works everything in the upper body in general very indirectly and nothing in particular effectively--suck.
2. Machine flies--if you must fly, don't use the bent arm variety--use cables or don't fly at all--synergy.
3. Kickbacks or any single arm triceps extension variation, such as single handed reverse cable push downs--no explanation needed.
4. "Balance work" -- balance boards, swiss balls (except for ab work), stability platforms etc..--for $49.99 and 20 minutes you too can waste your time, break an ankle and gain no muscle or cardiovascular improvement. I'm very against this crap exept for people with nerve damage or have been in commas for a long time and need to learn how to stand again.
5. High rep calf work--if you do 15 sets of 10 for your chest and 3 sets of 35 for your calves, please don't tell me your calves won't grow.
6. Any single arm dumbell lift off the floor, such as single arm clean and jerk. Injury anyone? See pullover description above.
7. Forearm work.
8. Any cable exercise that "resembles real world activities," such as swinging an axe.