A Garmin eTrex can do that, good battery life and it has an really simple interface. The only downside is the serial cable which costs about £20 and is required to get the data out. I made my own cable with an old credit card, a cable from an old serial mouse and some hot glue, works fine.
Most devices should log to GPX format or at least a format that can be converted to GPX. You can then load the GPX into something like Google Earth or to OpenStreetMap. Typically speed is calculated after the data is collected by comparing the timestamps between two adjacent points.