The first thing you will want to do is jail break your iPhone, you can jail break any iPhone firmware so I recommend flashing to the lates firmware to the one attached which is 1.1.4(iPhone1,1_1.1.4_4A102_Restore.ipsw) and restore your iPhone click on the restore button then finding the file you have just downloaded.

Make sure you sync all your images, contacts, and etc. before restoring. Then once you are done with that, download and extract the latest version of ZiPhone attached at the bottom. Open it up and run ZiPhoneGUI.exe. Once that is done do not click anything but JAILBREAK on the left, it will take a few minutes.

Once that is done, you can start downloading files from this site or go into the "Installer" and add the following Sources URL by clicking Source, then Edit, then Add on the top left:

http://www.iphone-emulation.com/repo.xml

Then go back to Install on the bottom left and you should see a new category called Emulators, and badaboom, badabing! You can start installing them!