IDrive is one service that meets the following requirements:

1. Backup onto an external database over the Internet.
2. Reasonable assurance the database is maintained to withstand foreseeable disasters.
3. Syncing capability for 150 GB or more that allows efficient backup at least once per day.
4. Reasonable assurance of data security (i.e., solid encryption method).

We're always talking about surviving massive disasters in the future, but what about surviving my everyday life right now? IDrive saves locally deleted files until I wipe them out on IDrive. This nice little feature has saved my ass on several occasions in everyday life, and is something I have not found in another service within this price range.

Again, regarding the issue of going out of business or out of date, I pay a monthly fee. I'll know IDrive hasn't gone out of business, or out of date, in the last 30 days at worst. Actually, I backup at least once per day, and so I would know if IDrive went out of business within the last 24 hours. Anyway, I have not read of any such problems with any online backup service.

Although I do admit TrueCrypt has its place, it still doesn't offer what I need based on my requirements here. I go through this exercise about once per year.