We use VMware Workstation a lot during our information security audit work and have lots of times when we just need to copy a file or two to or from a virtual machine and it would be nice to not have to wait to startup the VM, login, copy, etc.
VMware has a Virtual Disk Development kit (http://www.vmware.com/support/developer/vddk/) that contains a helpful tool for this problem. There is only a 32-bit Windows version but it works on 64-bit systems. Among other tools, the kit includes a handy command line utility called vmware-mount, also known as VMware Disk Mount. You'll find the utility in C:\Program Files\VMware\VMware Virtual Disk Development Kit\bin. [more]
Once it's mounted, you can work with that disk in Explorer, just like any other disk. To mount a local .VMDK to the M: drive, use the command:
vmware-mount M: {pathToVMDKFile}
You can even use this tool to mount remote .VMDKs, either on other Windows hosts or ESX/ESXi hosts. Here's some quick syntax to connect to a disk on a remote ESX/ESXi host:
vmware-mount K: "[storage1] WinXP/WinXP.vmdk" /i:ha-datacenter/vm/WinXP /h:esx3 /u:root /s:secret
You can get all the command line hints from the tool's documentation.