apple tv and roku - strong wireless? I have a broadband dsl at home, but my wireless signal isnt that strong in the living room. I am excited with getting one of these 2 devices, but I don't know how it will all work without cable.

If I am working at home or downloading stuff, then the available bandwidth is even lesser. Does that mean bad streaming and buffering? Will these devices let me buffer the movie when I am not at home and then watch the stream later?

Thanks.
The Roku HD has 802.11b/g WiFi. The Roku XD and XDS have 802.11b/g/n.
The Apple TV has 802.11a/b/g/n.

802.11n is the fastest network speed, and reaches the farthest. If the WiFi in your home is 802.11n, I strongly recommend choosing one of the players that supports that.