Jailbreaking a phone takes 10 minutes, and almost no work.
also, your explaination of the capabilities of a jailbroken phone are very inaccurate.
It doesn't take them more than a few days usually to break the new software.
Jailbreaking allows people to do the things with the iPhone that Apple will not allow out of the box. Also, many of the Apps that do not get approved for sale on the App Store end up on Cydia and Icy.
A good example is the Flashlight app, an app that used to be sold on the App Store, but was removed because it hacked the iPhones brightness to make the screen a much better flashlight. You can get it on Cydia for free.
In addition, just like the app store, there are apps that you have to buy, like the full version of PDANet for example, which allows you to easily tether your iPhone to any device that has WiFi and use it to share internet access.
Some of the Cydia and Icy apps I use:
Cycorder - Lets me use my 3G as a video camera, which isn't a problem for you as you have a 3GS.
WinterBoard - Complete customization of the look and feel of the iPhone interface.
Flashlight - Self explanatory.
xGPS - Turn by Turn directions for the iPhone, haven't gotten to mess too much with it yet, but seen videos of it being used.
ClearCam - Takes several images of the same thing, and averages them together to get a better quality picture. Also not really a big deal for you since you have a 3GS.
OpenSSH - Allows you to SSH into your phone to retrieve data (like getting the videos from Cycorder and such)
iMobileCinema - An addon for Safari that allows you to watch Flash videos embedded in pages.
UserAgent Faker - Tells websites you are running a regular browser, so you don't get diverted to mobile versions of websites.
MxTube - Allows you to watch and download YouTube videos, which you can retrieve with SSH.
So basically, in short, SpaceGhost really has no idea what he is talking about...
Also, these are the best skins money can buy for the iPhone.
http://www.bestskinsever.com/servlet/the-88/iPhone-3G-Skin/Detail