I did find LockCalendar very useful, but IntelliScreen was too noisy for my tastes.

I also enjoyed being able to hide apple's built in apps that I don't use. sbsettings was great too, being able to toggle wifi and data connections was pretty slick.

Dock was WAY to superfluously graphic. No use to me there. I only have 4-5 non-apple apps on my phone, so it's not necessary to group them or have creative ways to find them anyway.

I wasn't very interested in customizing the background or icons either. Thats a matter of preference though.

But really, for me, there weren't any settings that I couldn't live without. Jailbreaking was more of an intellectual curiosity than it was an endeavor into customization. I'd used my phone without it for nearly a year, and frankly I was used to it.

Certainly Jailbreaking is interesting, but for me, its not interesting enough to stay. I'd say 90% of my use of the phone didn't change after I jailbroke.