I'm using one of these to measure sea temperature.

The TINI is placed in the basement and connected to the Ethernet. 2 wires go from it, through the garden (under the ground) and out into the water. 3 temperature sensors are connected along the way. It's a so-called 1-wire (signal + gnd) net. 2 of the sensors are in the water, the other one is located just outside the wall.

A small Java application is measuring the temperature of all the sensors and put these into separate files on the TINI. Every now and then, a script, running on a Linux box, is fetching the measurements via FTP from the TINI. The data is then run through rrdtool to produce graphs.

The result is availible here. Be aware that since I'm not living at home at the moment, the page doesn't get updated that often. The data on it now is 2 weeks old. FYI: the whole project is in a prototype-stage, so there are some bugs here and there. Like the precision on the temperatures...

The TINI is very cool to work with since you have got lots of I/O and an Ethernet interface. It also supports PPP so you can, in theory, hook it up to a modem to allow remote access.