I have thought about jailbreaking my phone but I have heard about way to many people having problems with their phones after they do that even if they restore it later. I don't know that I'm willing to mess up my phone permanently. But it does sound VERY inviting.
I did like you said and I am using 4.3. Thank you very much for the info.
What you ought to do is jailbreak your iphone and purchase through cydia a program called "mywi 4.0". This program is 20$ upfront, but if you have an unlimited data plan from your carrier, you can use this. It's a personal hotspot, but better! And you only pay once, so it's less than a monthly payment on your carrier. As far as it showing up, look into Settings>General>About and scroll down to the bottom and see if you're really on 4.3. I'm stuck on verizon's 4.2.6 right now so i can't really give you a definitive answer :-\.
I forgot 4.3 isnt out yet. Well, there's pwnage tool, but if you aren't on a mac youre SOL. Jailbreaking is safe. I've been jailbroken for almost 3 years now with no issues.