By "rebooting" you mean SBF'ing? If that's the case, then yes, you will lose all of your non-stock apps. I use Titanium backup, but it will require you to root your phone again in order to reinstall all of the apps backed up with it.
On a side note, you can always delete the files that make root possible with a program like Root Explorer or a Terminal Emulator. Here are the commands below for the Terminal Emulator which you can get for free from the Market, Root Explorer costs a few bucks. I've also added some of other locations where the files may be hiding, so you might get a "No such file" error, which is okay.
Code:
su
mount -o rw,remount /dev/block/system /system
rm /system/app/Superuser.apk
rm /system/xbin/busybox
rm /system/xbin/su
rm /system/bin/busybox
rm /system/bin/su
reboot
If the "mount -o rw,remount /dev/block/system /system" command doesn't work for you...
Try "mount -o rw,remount -t ext3 /dev/block/mcblk1p21 /system"
For Root Explorer:
1. Open Root Explorer
2. Open system folder
3. Press the Mount R/W button at the top of the window
4. Open app folder
5. Long press on Superuser.apk and select Delete from the pop-up menu.
6. Press the back arrow.
7. Open bin folder
8. Long press on busybox and select Delete from the pop-up menu.
9. Long press on su and select Delete from the pop-up menu.
*If su and busybox are not in the bin folder repeat steps 8 and 9 under the xbin folder.
10. Press the Mount R/O button at the top of the Window.
11. Reboot the phone.
Any questions or problems, just repost here!
