External Hard Drive options??

[AthlonXP]

Just wanted a suggestion on which type of external hard drive I should look into. Its for a user at work that basically want it to sit at her desk and do auto-matic backups. Since our machines until the end of the year will still be on XP, I wanted to know suggestions on at least a 1TB external drive with software that would be best for just the basic backup of documents, and .pst files. Thanks in advance!