Carroll J. Boylan patented this gadget in 1995. Supposedly, you can load your dishes into a dishwasher without leaving the table:
A space-saving dishwasher has a washing basin having side and bottom walls and an open top, and a vertically shiftable rack assembly for carrying dishes. A shifting mechanism is coupled with the rack assembly for selectively shifting the latter between a lower cleaning position, wherein the rack assembly is disposed within the basin below the open top, and an upper loading position, wherein the rack assembly is disposed above the open top of the basin. The dishwasher further includes a lid member for covering the open top of the basin when the rack assembly is in the cleaning position. Structure is also provided for cleaning the dishes carried in the rack assembly, when the assembly is in the cleaning position. The dishwasher is particularly designed for installment within an opening of a substantially horizontally extending table-top or kitchen counter top.
Would you find this invention useful?
http://patft.uspto.gov/netacgi/nph-Parser?Sect2=PTO1&Sect2=HITOFF&p=1&u=%2Fnetahtml%2FPTO%2Fsearch-bool.html&r=1&f=G&l=50&d=PALL&RefSrch=yes&Query=PN%2F5687752 via Anticipate This!
Dishwashing machines are surprisingly water efficient. Now, that doesn't take into account the electricity to run the machine or the resources to make one, but in any case, they aren't a horrible solution.
@Vonskippy
I'd find it useful, not for the chance to stay seated (though, that would be AWESOME!), but for the use of the wasted space underneath my table. I could really use the extra cabinet where my under-counter dishwasher is.