Here is the first screenshot of a new tab in the SBackup configuration that allows you to automatically erase old backups. There are two options: plain and simple "keep backups for X days and then erase them" or the smart (and default) progressive trimming option in which you have more backups of recent times and fewer backups of less recent times.
Now that the interface is up, I will be coding the part that actually does the trimming. The tricky part is dealing with incremental backups in progressive purge scenario. I will need to do a lot of testing to insure that I get it right, before I release it.
ObNotebook: A happy DHL courier woke me up today and picked up my laptop. I kept the harddrive. The courier said that usually Dell guys return the notebooks on the third day, so I could hope to get my laptop back on Wednesday.