disk-utilitymacospartition
How is it that Disk Utility allows you to resize the partition that OS X is botted from live, while the OS is running? Can there be problems doing this? I would have thought that booting into recovery mode to do these things would be a requirement.
Here's what I mean, Disk Utility will allow me to "Apply" this change while booted in OS X:
I'm not sure whether clicking the "Apply" button is something safe to do while the OS is live. Is it? If so, how/why?
My suggestion
Don't try to resize from the Recovery partition. Boot into the normal partition and resize from there.
Background
diskutil list is misleading you. It is not the position of the recovery partition which is your problem.
I had a very similar setup, and here is the output of diskutil list for me:
#: TYPE NAME SIZE IDENTIFIER
0: GUID_partition_scheme *500.1 GB disk0
1: EFI 209.7 MB disk0s1
2: Apple_HFS Macintosh HD 423.6 GB disk0s2
3: Apple_Boot Recovery HD 650.0 MB disk0s3
4: Apple_HFS Temp Partition Test ... 74.8 GB disk0s4
5: Apple_Boot Recovery HD 792.2 MB disk0s5
Partitions 4 and 5 had a dev version of Lion on them. I have just used Disk utility to delete partitions 4 and 5 and resize partition 2 to fill the space.
This worked - Disk Utility resized the main drive with no problem. So what have I done which is different to you? Well, I resized the main partition from booting into the main partition not the Recovery Partiion. You can resize a partition that you have booted from in Disk Utility.
It makes sense that the recovery partition would "get in the way" if you have booted from it, so I suspect that above suggestion might work for you.
For all my partitioning, I use and recommend iPartition. It will allow you to resize partitions without deleting any data. It also works for Boot Camp volumes and other PC disks. It will automatically move partitions if necessary to allow resizing into free space that is located before the partition.
With iPartition, resizing a partition is as simple as selecting it, grabbing the resize handle and dragging. Not only that, but if you have several operations to perform, iPartition lets you queue them up and run them one after another, so you can have a cup of coffee while iPartition works. This feature, coupled with iPartition’s ability to automatically rearrange your existing partitions when necessary, makes iPartition the easiest partitioning tool that you’ll ever use.
Best Answer
Although I don't know what specific property of HFS+ allows a user to modify the current system partition while in use; my expectation would be that operations to blocks of storage that the filesystem is not currently utilizing are allowed.
Now if you tried to shrink the system partition below the current size of your system installation (the blue shaded area) disk utility would present an error.
EDIT
Just wanted to add some additional information that I came across. If you refer to the diskutil(8) man page under resizeVolume it states:
This seems to confirm my thinking above.