Just to let you know that in addition to online retailers (mwave=great), I bought my set from Costco in Sand City, CA for $80.
As far as general sofa use, I keep my keyboard and mouse on the coffee table, and if i am really too lazy to move, I just use keyboard equivalents of the usual mouse commands. These are particularly useful if your mouse drivers ever eat the big weenie (thank you, M$ windows update!).
TAB, shift+TAB, ALT+TAB, ALT+F4, and etc are your friends. Also, typing the first letter of a desired file's filename will bring up the first file beginning with that letter in windows explorer and the desktop. Enter executes your file.
In windows media player, all the multimedia functions on the logitech dual optical keyboard work as labeled. Also note that ALT+enter toggles full screen video.
Man, I could go on with this one!