VMWare offers a free software called VMWare player which you can use to work with virtual machines. of course It has less features than the Work Station version like the ability to make a team and record your WM session but you still can have your work done with the FREE version.
To install it in ubuntu do the following:
first download the software from HERE,
note: you will need to register to be able to download.
Change to the directory you downloaded your file to
issue the following command ,,,
gksudo bash ./VMware-Player-xxxxxxxx
where xxxx is the version details.
This will run a GUI installer, follow the instruction and after you finish,
you will find it installed in Applications, System Tools , VMware player