I use a not exactly orthodox incremental backup method with SyncBackSE. All new files or files that have changed are backedup everyday/several times a day, and compressed in a zip file. I keep all these compressed files, and when my external HD gets rather full, I dump them on DVDs and archive the DVDs (date, etc.). But this has to be done only once every couple months maybe, or more. Then, when I'm looking for something, I use 2 different methods to find specific files : WinRAR's searching capabilities inside encrypted multiple compressed files (works pretty quick and well), or Archivarius. I used to use Archivarius (each time I put stuff on a DVD, I indexed all zipped files content in Archivarius --> excellent!) but I stopped doing it when I decided that everything would be encrypted... Of course, if I was using TrueCrypt, it would still be possible... But I haven't managed to devise a new strategy including truecrypt.