A guy I know has 1 of each of these for sale. I know nothing about buying used phones, sooo some info would be nice.. lets see. I have a cingular phone (razr), and these are both cingular. I assume I can take my sim card out of my current phone and use it in both of these? -- I really like how the SK3 works.. w/ the internet and AIM etc. I know the treo can browse the web but can you get on AIM w/ it? One more.. If these phones do have web browsing / AIM, how does that work w/ my current cell phone plan? Will I need to contact cingular and have them change all my stuff?