Not practically, the best you can do is copy to/from the tape drive/hard drive for viewing. The data transfer rate is much to slow, and the tape is sequential access, which makes the seek time enormous.
Imagine if you were looking for a bit of information at the other end of the tape, you'd have to wind through all the tape, which may take minutes. If this were on a hard disk, you could do it in less than a second.
This is not practical. If you have to, you can d/l something, and store it on the tape drive for further viewing, but you couldn't watch a movie or play music off of a tape drive, it's simply too slow.
Hard drive space is cheap, why not go get one of those new 50 GB hard drives and hook that up? What exactly are you trying to do? A writable CD-ROM would also work much better than a tape drive. As always, I hope that helped!
Disclaimer:
Beware: Studies have shown that research causes cancer in lab rats.