I was looking at my 10 gallon, and under the water level, a couple inches down the glass, there's a translucent little blotch with a bunch of greyish spots in it. Are these snail eggs? Can't really think of anything else they could be.
Its a very good chance that they are. Be prepared for an inasion! There is usally a little bit of a snail outbreak at first and then they die off leaving a reasonable amount.