While very reliable, my weather station computer was old, outdated, and power hungry.  While searching for an appropriate upgrade, I came across plug computers  They are small (slightly larger than a pack of cigarettes), power efficient (draws less than 5 watts), less expensive than a full size computer, and runs embedded Linux.  I ordered a Guruplug Server from Global Scale Technologies, along with their JTAG accessory in case I managed to brick the computer.  Good thing too, as it took me no time at all (like maybe 2 hours) to render it un-bootable.  How did I manage to do that, you might ask.  I did the following:

• apt-get update
• apt-get upgrade
• apt-get dist-upgrade

After that the computer failed to boot.  That started me down the path of getting the JTAG to work and upgrading uBoot.  Then downloading and installing the kernel and file system.  Now it could boot again.  I ended up adding an 8GB Class 10 microSD card and installing Debian Linux on it.  Then modifying the uBoot parameters to permit booting from the microSD card. There were additional tasks, such as getting it to be a stable wireless client, installing software, and configuring it the way I wanted it to.