I've got a slant-top 10U rack from SKB, and I want to use the top for touchscreen monitors and other small electronics. I can get a tray meant for vertical racks like the one in the top-left, but how about a rack whose mounts are parallel to the ground?
It's a Windsor "The Hour". Love how much it kicks my butt just riding it around town, makes my commuter feel easy-peasy. I took a 2-day course in bike fixing/maintenance recently and with this simple bike (it's a fixed-gear), I feel like I can fix/upgrade so much of it myself now.
For the bike nerds: 52cm Windsor The Hour Upgraded with: Fyxation Gates Pedals and Straps Front Brake (bought used from CityBikes, installed myself) $5 Riser bar from local used parts bin (http://www.pdxbikeshop.com/), sprayed white with Krylon, put some blue Oury grips on. Running 48/15 Fixed (stock setup from BikesDirect)
I know the handlebars are a bit ridiculous, but the frame is a smidge too large for me and this setup is super comfortable on my back & arms. Want to play with an adjustable stem to find an angle at which I can attach some lower bars for a more compact setup.