On tv I often see someone zoom into part of a picture, ie. a logo etc. and then bring it into focus. Most of the time when I try to enlarge a part of a pix or zoom into a part of it the pixels are distored and jagged. IS there software that can do the above mentioned or is that just some tv magic? Thanks

TV magic.
You can't add data that isn't there.
Well, you can, but not in a manner meaningful to us humans.

Sometimes I watch a little bit of the show 'Las Vegas'.
Whenever they pull this kind of magic, I just giggle.

Although, it's been awhile since I looked seriously into this technology.
As far as I know, it's still magic.

yeah, Stroker's right, pure magic...

of course, you can make spectral analysis of the enlarged pic and push/boost/copy higher frequencies for sharpening; or, if the shot is coherent enough, you can try to extrapolate more data from subsequent pix [i think there are few papers on this on citeseer], but that's about it...

also, as tv signal is noisy as hell, the sharpening phase doesn't give any good results...

and exactly as Stroker says, you simply can't get data that are not there [don't forget that tv signal is in itself digital, thus loosing lots of information]...

This is about as close as I've seen anyone get. It's good, but it's not magic! http://www.focusmagic.com/exampleforensics.htm