I found this info and the disk images at http://www.ffnn.nl/pages/articles/linux/vmware-player-image-creation.php

Here's how to install a LiveCD ISO into a VMware Player-controlled disk image under Windows XP:

1. Download the VMware Player application: http://www.vmware.com/download/player/ and install.
1. Create a subdirectory, e.g. `C:\Documents and Settings\smith\Desktop\dfbsd\`.
1. Download the attached VMware-compatible sparse IDE disk image stored in `20GB-ide.zip` and extract it into that directory.
1. Create a VMware virtual machine configuration file with the extension `.vmx` in that directory, e.g. `dfbsd.vmx`: see below.
1. Change the parameter `ide1:0.fileName` to match the name of the ISO image.
1. Double-click on the `.vmx` file.
1. Type control-G to get mouse and keyboard focus into the VMware Player window, and proceed with a normal install.
1. Install to the whole disk, choose `lnc0` as the network device, install the boot block.

The vmx config:

     displayName = "DragonFlyBSD" 
     config.version = "7" 
     virtualHW.version = "3" 
     scsi0.present = "TRUE" 
     memsize = "192"
     MemAllowAutoScaleDown = "FALSE" 
     ide0:0.present = "TRUE" 
     ide0:0.deviceType = "ata-hardDisk" 
     ide0:0.fileName = "20GB-ide.vmdk" 
     ide1:0.present = "TRUE" 
     ide1:0.fileName = "LATEST-Devel.iso" 
     ide1:0.deviceType = "cdrom-image" 
     floppy0.present = "FALSE" 
     ethernet0.present = "TRUE" 
     ethernet0.connectionType = "nat" 
     usb.present = "TRUE" 
     sound.present = "TRUE" 
     sound.virtualDev = "es1371" 
     sound.fileName = "-1"
     sound.autodetect = "TRUE" 
     guestOS = "other" 
     ide1:0.autodetect = "TRUE" 


You can tweak `memsize` to adjust the memory. By default, VMWare Player creates a VLAN and does DHCP, so running `dhclient` works. I haven't tried to install X11. I haven't tried the Linux version of VMware Player yet. I tried the SCSI disk images, but they didn't work immediately, so I gave up and used the IDE image.

If you want to do anything fancier, you'll probably need VMware Workstation.