While these things were around when I was born, I'm grateful for indoor plumbing and the invention of plastic.
As for what I now take for granted that I didn't when I was a kid...VCR, like Phoenix32890 the cordless phone, microwave (although I think we were one of the first in our area to get one...I wonder how badly it leaked?), I'd say computer except I don't take it for granted -- yet...beltless feminine hygiene products, the remote control (for the VCR, t.v. and stereo), and...that's all I can think of at the moment.