More information is required. How much information are you talking about? A lot of companies charge per hour, so if you have a significant amount of data, it gets into money pretty quickly. Storage is cheaper than recovery, but $50-$500 an hour is not at all uncommon depending on how complex your environment is.
Assuming you have all of the original media for your computer and the applications, you can just dump the data to an external hard drive (320GB for $90 from BestBuy, and they ain't the cheapest)
http://www.bestbuy.com/site/olspage.jsp?skuId=8188114&type=product&id=1164155964057
You can just copy it and put it on a shelf somewhere, that's not a *bad* backup strategy, assuming you do it consistently.
Hiring a company for an individual is usually cost-prohibitive.
You should look through your drive contents and get a good idea of how much data you have, and how often you want to back it up, and how many copies of the backups you want to keep.
The more of each number, the better your backup needs to be. If you want complete fault tolerance, and keep the last 7 backups in a useable state, you might be overburdening a simple external hard drive, but you're still nowhere near the level of needing a 3rd party solution.
If you want to keep system state and data available, consider buying another hard drive (internal or external) and using a cloning program like Ghost or BackupExec, this will let you store you data as ISOs or Image files instead of the file structure currently on your drive. It takes less space, but it requires a bit more know-how and is more time consuming to restore the data to a usable state.
There are several brands of inexpensive tape drives you can use, and your rotation is limited only by the number of tapes you want to buy. At work we use a jukebox with 24 400/800GB tapes and rotate them daily, with 15 kept off-site. You can employ a similar strategy with single tape drives, although it usually entails buying a SCSI card and special software.
Hope that helps,
Odd