I think most who have and use Firefox will say the best feature is the add-on's like Adblock. Well now you can add adblock to MobileSafari.
Now do you have to jailbreak your iphone or ipod? yes
You can read more about it here: clicky
To install AdBlock for MobileSafari, you will need to jailbreak your iPod Touch or iPhone and install Cydia on it.
You probably want to have a look at tutorials on Google if you haven't done it already.
AdBlock is hosted on BigBoss repository, so you do not need to add a new source to Cydia. Simply open Cydia and search for AdBlock.
If you can't find it, make sure you have installed the "Community Sources" package in Cydia.