ETHO said:but do I have to jailbreak in order to switch to straight talk on my iPhone 4 (at&t) I have no clue how to jailbreak I never get it right or mis-understand what to do
You don't have to jailbreak.
However to get MMS (picture/video messages) you have 2 choices.
1) jailbreak. (very easy with the new 5.1.1 jailbreak. Just pug in phone, click "Jailbreak" and wait for it say it's done. Literally. Click a button and wait for the success message) and install TetherMe. TetherMe not only activates the native tethering option in the Settings.app but it allow you to edit the APN settings. Find the Straight Talk APN settings on the net, and enter them in the Settings app.
2) Use iBackupBot and edit certain strings do code in a backup file and restore to that backup.
I personally think its a much better option to just jailbreak and install TetherMe.
1) Update to 5.1.1, (best to restore and setup as new device and my from backup)
2) download Absinthe from greenppis0n.com(save to desktop)
3) Open Absinthe wait for the files to be extracted.
4) Open the Absinthe folder that was extracted to your desktop
5) Click on "Absinthe.exe"
6) plug in iPhone
7) click "jailbreak"
8) wait for the success message from within Absinthe and your done.
It just watch a YouTube video.lol way easier.