I was having longs backups as well that were driving me crazy. I tried turning off crash reports and it did not work for me. I found this fix on the Apple discussions site. I performed these steps last week and ever since my backups/syncs have taken 3-5 minutes instead of 1+ hours. It took a little time to implement, but for me it was worth it. Seems that it has to do with corrupt app installations hanging up the backup process. Give it a try and report your successes/failures! The end of the message suggests not to install/update apps directly on the iphone, but I have done it without adverse effect.
"Go into iTunes Edit/Preferences the last tab sync disable auto sync for all iPod and iPhones. This does not fix it it is just the first step do not stop here.
Next connect your iPhone to the computer. Once it shows up in iTunes go into the last tab Applications. Uncheck sync all apps. Now Click apply. Now click sync. it will remove all the applications! After it is finished unplug the iPhone. I bet you will have at least one app still on the Iphone, maybe more. Hold any icon down until they jiggle. tap the x's and delete all the remaing apps. You may notice after you delete each app that a little spinning circle is next to your 3G icon on the top right hand side. Let it finish spinning before you delete the next app.
Once you have deleted all the remaining apps (That had corrupt data that was causing your long back ups!) do a hard reset. To do this hold the sleep/wake button and the home button until the red slider appears at the top of the screen. Slide it over and the phone will power off. You will again notice the spinning circle. Once it finishes wait a few seconds and power the iPhone back on by pressing the sleep/wake button.
While it is booting back up go into iTunes again turn the auto sync back on! Now connect the iPhone to the computer, let it backup and sync. Now it goes so fast you may want to cry or laugh. Now after it finishes go back to the applications tab. Click sync apps again, but make sure you have the 2nd circle checked. This box is sync selected apps. Make sure all the boxes are unchecked! Now slowly begin adding apps back to the iPhone. I have done as many as 5 at a time. Check the boxes then click apply, then sync. It will backup then add the applications and sync all other information. After the sync you may notice that little spinning circle is next to your 3G icon on the top right hand side. Let it finish spinning before you add the next app.
Here is the kicker! DO NOT update or install apps from the phone! Only use iTunes to install and or update apps until they get the bug fixed!"