I use the EggBeaters and love them. Entry/exit is very easy (easier than SPDs even), but your foot is very secure, and it actually feels like you have a good platform under your foot. At a green light you should be able to immediately clip in, and if not you can still pedal without difficulty.

I haven't tried the Candys, and don't know how they'd work without being clipped in. The SPDs Veronica mentioned would probably work best for that type of thing; that's what I used when I first went clipless.

But the EggBeaters/Candys do look cool (at least to some of us). And they're lightweight!