I have used tapes in the past but have settled on a new solution. We do have a well wired home, with cat5 to our detached garage.
We now use a 1Gb Buffalo Terastation Pro and backup to a file accessed via share, housed in the garage so it is physically removed from the computers.
The teratation has 750GB when configured as a raid array, appearing as a workgroup computer shared filesystem. You can get 2Gb versions giving 1.5Gb in Raid config.
Each machine backs itself up to a directory on the share. We keep 2 backup files - the first is recycled every week, and has daily incrementals. The second has a weekly incremental added to it and is never recycled until it gets too big, when we archive it to DVDs and start again.
You can obtain any file from history at weekly intervals, or any file in the last few days, and this is way more than the average need.
The downside is that despite having a gigabit ethernet interface, the terastation won't transfer more than about 700Mb/min, but as we do everything overnight, this isn't a massive issue.
The plus side is that the 1Gb terastation is about £450, never needs tapes and DVD-ROM archiving (for us) is only needed about every 6 months.
BW