My community group would like to install computer screens around the neighborhood displaying CTA Bus Tracker times for that bus stop. We can get 19-inch monitors for relatively little money these days, but having an entire boxful of computer down below seems like a waste of space and power when the only thing it ever needs to do is display a single browser window. These would be inside shop windows, so weather and theft are not much of a concern.
I keep thinking about Arduino boards and their ilk and wondering if there are similar under-$100 boards or CPU modules that function as a full modern computer, which we could just attach to the back of the monitor. We’ll use something like LogMeIn to monitor, reset, and alter the displays once up and running, so we don’t even need an attached keyboard and mouse. We’re not afraid of Unix as long as we can easily get a browser onto the screen.
It sounds like the sort of thing that could perhaps be done by hacking one of those Wyse thin client boxes, or similar.
You could do worse than start here: http://www.linuxfordevices.com/
There is a whole ecosystem of tiny little single board systems that have more than enough horsepower to do what you want. A quick peruse of the bus tracker site suggests that they have a very light footprint, and so the most modest of compute and browser capabilities will do. Thank goodness it isn’t some horrendous Flash ridden monstrosity.
Pretty much any computer can work a browser (if you aren’t picky about which browser). Cell phones can do it.
Is cost an issue? Generally the smaller you go, the higher the cost. You can get linux on a wallwart (plug) though I don’t recall any with a monitor output. They’re intended more as little servers I think.
You can buy “all in one” machines that look just like a monitor with the computer built in. They tend to start around $500.
If you have a monitor already you can go small and get a thin box (I’m thinking an “Eee Box”, you can google it).
If money is an issue any old discarded box will work. Put it in a different room and get a long monitor cable 
There are some miniATX boards that are under $100 and come with an atom processor. I bet you could put one of those in a case for no more than another $50 or so.
Here’s an example of a barebone kit for one of these. It’s case power supply, mobo and CPU ready to go for $109: Jetway JC200S-B-J7F21GS Black Mini / Booksize Barebone System - Newegg.com
All you need is to add some DD2 memory. Maybe an extra $20 investment.
I’m looking into getting one of these to use as a cheap Home Theater PC for the bedroom.
Edit: You don’t even need a hard drive, you can boot into Ubuntu from a thumb drive.