Is it possible to run mobile apps on computer? To be specific, I have a Nokia n95 phone running on Symbian OS
There are a few emulators out there that can let you use a certain subset of all J2ME apps on your computer, but native executables are almost impossible to run on a computer short of a manufacturer-provided emulator.
All of the iPhone, Android, and BlackBerry have simulators for running mobile applications on your PC (well, Mac in the case of the iPhone), but they're designed for debugging applications you're developing not general usage. Other Mobile OS developers probably provide similar software for their developers.
If you just want to use $hot_iPhone_app on your desktop, then no, not generally speaking. That's not how it works. You'll have to look for a desktop-based alternative.
The short answer is no. You would need cell phone service from your computer to get any use out of them even if you did find a working cell phone emulator, which is highly unlikely unless you're talking about Android. The good thing is that there are usually PC equivalents of mobile applications if you look around for them.
A symbian emulator might do the trick