Is it possible to repartition hard drive from which Mac OS X boots? I have the following problem. I wanted to have dual boot to Ubuntu, so I've created 3 additional partitions using BootCamp (I probably created freespace with Bootcamp and then used Ubuntu installer to partition the free space, I cannot remember exactly, since this was 2 years ago). Now I want to remove these partitions to reclaim space, but the only thing I can is to reformat them to use MacOsX HPFS+. I tried booting from the Mac Os X install CD, but that did not help. When I try to remove partition by pressing - in Disk Utility it just throws some error about MediaKit. The only thing I am allowed to do is to reformat the disk entirely. 

I've searched this site and in some answers I've found that you cannot change partition table on hard drives with MBR (i.e. if you have a mac os x boot on one partition, you cannot change the partition table). Is this really the case? Seems like a huge restriction on Apple's part. 

Or is it that bootcamp (or ubuntu installer) has written wrong partition table, and now there is no way to change it?

I'm using udpated Snow Leopard.

Here is the output of diskutil:

ivrin:gdpp mpiktas$ diskutil list
/dev/disk0
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      GUID_partition_scheme                        *250.1 GB   disk0
   1:                        EFI                         209.7 MB   disk0s1
   2:                  Apple_HFS Macintosh HD            195.3 GB   disk0s2
   3:                  Apple_HFS disk0s3                 11.9 GB    disk0s3
   4:                  Apple_HFS Linux Swap              4.2 GB     disk0s4
   5:                  Apple_HFS freespace               38.0 GB    disk0s5
You should be able to repartition uour HDD using Disk Utility (see this related question). You should also be able to remove the BootCamp partition using the Boot Camp Assistant.