Anybody help with a positive critter ID?

[hooked82]

So I looked in my overflow today and saw about 20 of these little pod looking things. They are white, a little over 1/4" tall, have 3 little "legs" on the bottom, and some sort of skirt on top. The top looks like its an opening or something. Maybe somethings about to hatch and take over my tank? I got a couple pictures, they're crappy so its hard to tell what they are. Maybe from just the outline somebody could give me an idea if I need to get them out asap or if they're ok. Thanks!!

 

[chris&barb]

they look like pineapple sponges to me. good to have