Yes. You need to have the “Personal License” in order to do this in compliance with the license terms. Simply install Resharper, and input your name and registration key.
According to: http://www.jetbrains.com/resharper/buy/buy.jsp#personal_licenseTerms
A Personal License is a named-user
license which restricts the use of the
software to the person who purchased
that license. The license allows for
installation of the software on
different computers (at work and/or at
home), provided that multiple
instances of the software will not be
used at the same time.
If you have purchased another license than the Personal one, I would suggest you contact Jetbrains and ask them if your license allows it. In particular, I think that whether you can do this with the Commercial License, would depend on the exact usage scenario.
I personally have a Personal license and use ReSharper on both my work pc, home pc, and on my laptop – with no problems. You can only use it on one of the installed computers at the same time.