There is a way to have multiple games on the same user account, too. I hate switching user accounts, so I do it this way instead.
What you do is you install the game twice (or more), but choose different names during the installations. For example, you might have:
C:\Program Files\Virtual Families\
C:\Program Files\VF\
C:\Program Files\LDW - Virtual Families\
C:\Program Files\Another Virtual Families Copy\
Here's what I have right now:
Once you have installed them, open the folders and change the name of the *.exe files so that they are all different. For example, the one in the folder Virtual Families might be called VirtualFamilies.exe while the one in the VF folder is called VF.exe and the one in the LDW - Virtual Families folder is called LDWVirtualFamilies.exe
Here's what mine look like (but I don't recommend using 1.0 in the name, that was a mistake I made... just notice that they are named differently):
If you got your game from another site, like Reflexive, you might have to rename other files so they match. I don't know if other sites do this, but I know for Reflexive there's a file called *.rwg, and it needs to match the *.exe file identically.
This is what a Reflexive game looks like:
The last step is to create shortcuts to each of your *.exe files and put the shortcuts on your desktop or wherever you want them.
Ta da! Each game will run completely separately from one another. They can each have their own mods, too. You can have as many families as you want this way, and never have to switch user accounts.
This is what my My Documents\LDW\ folder looks like (this is where the saved games are, of course):