Yes man there is.

In the installer, go to "All Packages" and look for SIMport. The only thing that iSIM has over it is the application's springboard icon. SIMport's interface, however, is great and it is free.
With regard's that statement about your Nokia phone not being compatible with the mac for syncing, I do not know what Nokia phone model you have so I may not know the validity of that statement. It is a known fact that the mac is compatible with a great deal of Nokia phones. You can
check here for a list of devices that are compatible with iSync. And if you want, you can check some
additional plugins or even google what you're looking for.
Let me know if you get through.