As rpstewart has already mentioned, the market for these type of devices seems to have died as a result of the tablets that now exist.
Canon and Epson made devices that allowed you to upload photographs and then view them on a fairly large screen (for the time), problem is they were expensive.
The Canon Media Storage M30 and M80 and the Epson Photo Viewer series (P-2000, P-3000, P-6000, P-7000 and P-9000) were available but I suspect are probably discontinued/in short supply.
Personally I would invest in more CF cards, they're fairly cheap nowadays. Personally unless the picture is massively under/over exposed or obviously blurred I never delete them. I keep them on the card until I get them home and then view them on a monitor