1 Question why would you want to jailbreak ya iphone4?
You dont need to do that, u have the best phone on the market and have everything on the phone u need,think about it.
Just some friendly advice dont do it, i did it on my iphone 3g and it kept crashing its not worth it,i have the new iphone 4 now and wouldn't dream of doing it to this phone.
the phone does offer a lot but jailbreak will always be needed for some, and even though the iphone 4 does offer a lot some jb apps are just too good to have to go with out..
for example sbsettings or vlc player also installous for some who liked those cracked app store apps/games. ssh is a MUST you can manipulate files upload files and delete those default apps like stocks wtfrig do you want that on my iphone for? why cant i officially delete it? no bluetooth file transfer
there are so many reasons for some one to want to jailbreak, but having said that i am with you on this one i am not going to jailbreak either its just so much hassle and even though you can get good apps and games every firmware you need to wait for jailbreaks and imo its just to much hassle..
you should avoid the jb,