This is a very simple rsync backup script, very much inspired by rsnapshot,
but with very few dependencies (just a bash and rsync) and backups are pushed
to a server rather than pulled in.
Incremental snapshots are rotated in hourly, daily, weekly and monthly intervals.

To use, put the backup script in ~/bin
Configuration must be put in ~/.backup/config and regular rsync includes/excludes in
~/.backup/exclude

I run this with the following crontab entries:
@reboot $HOME/bin/backup > $HOME/.backup/log 2>&1
49 * * * * $HOME/bin/backup > $HOME/.backup/log 2>&1

The result will look something like this:
lrwxrwxrwx  1 miklo miklo   10 2011-12-13 20:11 daily.0 -> ./hourly.6
drwxr-xr-x 18 miklo miklo 4096 2011-12-12 19:49 daily.1
drwxr-xr-x 18 miklo miklo 4096 2011-12-11 20:50 daily.2
drwxr-xr-x 18 miklo miklo 4096 2011-12-10 11:49 daily.3
drwxr-xr-x 18 miklo miklo 4096 2011-12-07 21:49 daily.4
drwxr-xr-x 18 miklo miklo 4096 2011-12-07 20:49 daily.5
drwxr-xr-x 18 miklo miklo 4096 2011-12-06 21:49 daily.6
drwxr-xr-x 18 miklo miklo 4096 2011-12-13 21:49 daily.7
drwxr-xr-x 18 miklo miklo 4096 2011-12-13 21:49 hourly.0
drwxr-xr-x 18 miklo miklo 4096 2011-12-13 21:49 hourly.1
drwxr-xr-x 18 miklo miklo 4096 2011-12-13 20:49 hourly.2
drwxr-xr-x 18 miklo miklo 4096 2011-12-13 20:11 hourly.3
drwxr-xr-x 18 miklo miklo 4096 2011-12-12 23:49 hourly.4
drwxr-xr-x 18 miklo miklo 4096 2011-12-12 22:49 hourly.5
drwxr-xr-x 18 miklo miklo 4096 2011-12-12 21:49 hourly.6
lrwxrwxrwx  1 miklo miklo   10 2011-12-13 21:49 monthly.0 -> ./weekly.4
lrwxrwxrwx  1 miklo miklo    9 2011-12-11 18:49 weekly.0 -> ./daily.7