While Blu-ray is best known for movies, it's also an excellent archival data storage medium for anyone with a Blu-ray writer. A standard dual-layer Blu-ray holds 50GB of data, over ten times as much as a standard recordable DVD.
Most desktop PCs have room for an internal Blu-ray writer, while laptop owners can take advantage of a wide range of external writers. USB 2.0 writers are limited by the speed of the connection, but eSATA and USB 3.0 models, which are easily compared on eBay, remove that bottleneck. Find everything from internal to external and even standalone writers quickly on eBay and archive your data accordingly.