Ask HN: Why Jailbreak my iPad2?

I have always thought I would be against jailbreaking my iOS devices. I have friends that have done it but they dont seem to have any real reasoning or take advantage of anything spectacular. One of them simply jail broke his iPad so he could password protect his apps (i.e prompt for a password on app launch...)

Then I got to thinking. What are the real benefits?

I code in C/C++ and standard web stuff. Could one then load gcc some how?

Are there better network tools like nmap, wireshark, etc, etc

Can anyone explain some true advantages to a developer/hacker/someone who always needs to help someone out in a pinch and would rather not carry a MacBook around all the time?