Quite sometime back, we had told you about a registry hack that allowed you to run multiple instances of Yahoo messenger on your PC.
If you are not comfortable with editing your registry, a simple freeware called Yahoo Messenger Multi Login will allow you to perform the hack by clicking a button.
Once you apply the hack you will be able to run multiple Yahoo Messenger instances on the same PC and login using separate IDs.
Pretty useful if you make use of separate ids for work and your personal use. Of course you might achieve the same by using a multi-protocol IM clients like Digsby.
Yahoo Messenger multi login is a portable software and does not require any installation.
Download Yahoo Messenger Multi Login