I have the ultralife trap at home it works ok you need to be there to watch it. I hear people have great success with baited soda bottles. All you need to do is cut the top off where it starts to taper and invert the top bait the trap and the fish swims in. I'll be in manhattan Fri nite from 3-11 pm. But you'd have to come to harlem to pick up the trap.
You can just take a regular water bottle (like the small poland spring bottles), cut off the top (where the bottle goes from angled to staight down), turn the top around and stick it back in the bottle. Tie a nylon string around the top, put food in the bottle, and wait.
I guess this would only work with smaller fish but you could probebly do it with bigger fish if you got a bigger bottle/opening.
I made a mantis trap with an old siphon tube and two clear glass funnels just big enough to snug in on 1 end and the other glued in on the other end. I put food inside and walk away.