I've downloaded and installed their MCS Storageview tool, which displays all the logical partitions (so not just the vmdk files) of all your running virtual machines on ESX 3.x or VC 2.x.
The tool can also display how much of the logical partition is free space, so the admin can decrease the partitions if needed.
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The tool can be downloaded here. You'll see on the page that there are more cool tools to download, such as the snapshot checker.