Can I remove the sim card on my iphone and put it on a different iphone?

Can i remove the simcard from my iphone 4 and put the sim card in my other iphone? Will things be erased? Or what?

All your data is on the sim card, so it should all be still there if you put the sim into another phone.

Nothing is actually saved to the SIM card, all the SIM card does is hold information about your carrier.

I agree with justme post.
Before swap your sim card, Make sure your another iphone is unlocked one. If it's locked to other than your current carrier, you will need to unlock it. For unlocking you can approach your service provider or else try to buy an unlocking service from any one of the online unlocking service provider like http://www.simpleunlocking.com/apple/rs16wp8/ I hope it will be very useful to you.