First off, let get a couple of things clear. Its not copying the dvd that takes so long, its converting the format to one that can be played on your itouch. You can actually copy a movie with a fast drive to a computer in less than 10 minutes, but realize, that 8GB movie is still going to be 8GB. Further, dvd uses the mpeg2 format which your itouch doesn’t seem to even support (not surprising as mpeg 2 is an old, low compression format that would be crappy for portable players).
You have to convert it to a format that the itouch can play and that is what is taking so long. I haven’t really used dvd fab so I couldn’t tell you how it compares. You might find another program that is a bit faster but its still going to take a long time. I have been converting a lot of movies to h.264 (an mp4 format that your player can play) recently using nero, and on my athlon 64 3200 it takes 3+ hours while on my conroe e6300 it takes 2+ hours.
What matters for conversion the most is processor power, period. A faster processor will convert faster. If you have a decent amount of memory, more wont help. A faster drive most likely won’t help either. Better software might help. but even with the best, its going to take a few hours, depending on the speed of your computer. Fyi, what processor does your computer have?
You could try nero (there is a free trial), just to see how the speed compares. I can get you started with that if you like. You can also look here for guides on converting dvd to mp4 (h.264 is probably the best for good quality and small size but it takes the most power for the player to decode).
Look here for guides (that may use one or many programs)
Under the Format Conversion dropdown, change it to dvd to mp4, acc or h264 (all are mp4 formats).
Here are programs that can do it (some free)
Under the Tool features dropdown, change it to the same format conversions mentioned above and then click search.
One little side thing that might help just a little bit (at least it wont have to be accessing the dvd drive for hours), copy the movie to your hard drive first. Download dvd decryptor (it discontinued but google and you should be able to find it somewhere), and with it in file mode, copy it to your hard drive. I can help with that too if you like. On a fast dvd drive, it takes less than 10 minutes. I’m not sure about dvdfab but nero can just work from the folder it creates on your hard drive.
One last thing. Rereading your post, if the computer is 4 years old, then that is most likely the primary cause of the long times. Your computer may just be that slow, and converting is almost completely Dependant on the speed of the processor. You might be able to improve speed with different software, but on a computer that old, its still going to take several hours.