Definitely "Macro"

[Lava Lamp]

This guy is about the size of your thumbnail. Anyone care to make an ID?

[almo]

Where did you find him?

[paulnj]

Yes, do tell.

[Lava Lamp]

Found in Southeastern US. Specifically in a swimming pool near a small lake in the suburbs fronted by woods -- mostly scrub pine and palmetto -- on three sides. His skin was smooth and more uniformly gray looking with the naked eye. The spots come out more withthe micro/macro and flash. Pretty small. Smaller than a green tree frog. I said he would fit on your thumbnail before, but since thumbnails vary, I'd say he would fit easily on a quarter. I think he is noturnal. I only find them in the pool in the morning occasionally.

[paulnj]

SPRING PEEPER... I was thinking that, but your discription confirmed it .. TO ME atleast ;)

They are variable throughout there range, so pattern can or can not be key to ID.

[almo]

Paul beat me to it, but I concur, Spring Peeper (Pseudacris crucifer)