Infinidock is a nice project by a fellow by the name of chpwn, and allows you to have a horizontal scrolling dock on your iPhone or iPod Touch.

Full dock customization: scrolling, adjustable icon amounts, and more! Add as many icons as you want, and the dock will grow to accommodate them, and set how many you want on every page. The ultimate dock customization tool, by one of the developers of ProSwitcher. Please report all bugs and submit all feature requests via email so we can take a look!

This is perfect for people who want more than 5 icons on the Dock without making the Dock look wack. Simply drag and drop the icons into the Dock. You will then be able to swipe to scroll through the icons as they remain in your dock on each page.

This app is available on Cydia for a low price of $0.99

Note: This app requires you to have your iPhone jailbroken with Cydia installed