Universal Impressions would be my pick. I have used it alot & it never fails. I have come up with some clever ways to hide the gimmick. Its good for walk around. The Tommy Pad by Inner Mind Productions, I have heard nothing but good things about this.Apparently you can take the pad back from the volunteer, make your peek as you're closing the pad & never have to touch the pad again. There is no fumbling,or anything that might suggest that you are up to something. This is definitely going to be my next purchase. When I get it I'll let you know how good it really works.
Universal Impression RULES; DEFINITELY my MOST performed and remembered effect - when I perform this is the ONLY effect I do and it leaves them speechless - VERY, VERY, VERY POWERFUL. And funny thing too is The Tommy Pad was going to be my next purchase, LOL - I read that when just less than $15, you can create 10 Tommy Pads out of it - I'm looking into this just incase I forget UI at home and need to make a imp. pad on the go.