iPod touch or iPhone with slow backup

I used to have an incredibly hard time getting my ipod touch to backup on my computer. I would hook it up to itunes and hit sync, then I would come back 2 hours later and it would not even be half way done. This was incredibly annoying. I was trying to update apps and put new music on, but it would never let me. I finally figured out that the problem was downloading apps over the wifi. There was some kind of problem that occurred when I would try to transfer the apps I purchase over wifi on my ipod touch. I ended up having to restore my ipod back to its original settings. Then I went through and put each app on one at a time. I would check mark one app, hit sync, then I would right click on the ipod in the left of the screen and hit back up. I continued to do this for all of my one hundred or so apps. As I put more and more apps on, it took a little longer for them to back up, but nowhere close to 3 or 4 hours. I was very happy with my backups now only lasting minutes compared to hours. Looking back on it now, I might could have done it without doing my apps one at a time. I think that I could have just checked them all, however, the backup for the very first time would have taken a long time. But I think that the first time would be the only time that the backup would take a long time. Now I never transfer any apps over to my computer from my ipod touch that I got via wifi. I believe that it is still ok to download apps over wifi, but just don't transfer them to your computer because it will mess up your backing up. So just don't transfer any apps to your computer from you ipod touch or iphone that you have downloaded via wifi. If you do this, then you will have no problem backing up your ipod or iphone