Unimaginatively named Browser Changer, the tweak is free and downloadable now via Cydia.
Once installed users can set the browser that will be opened when tapping links in emails and the like, as well as overriding the way Maps and YouTube are opened when tapping the relevant links.
This is a must have tweak for those of you who are a fan of Skyfire, PreBrowser, Droid Browser, Atomic Browser, CloudBrowse, or Opera Mini.
Ou will, of course, need to have a jailbroken iPhone or iPod touch to install it. Follow our guide posted here to jailbreak iOS 4.3.1 using Redsn0w or posted here for PwnageTool while preserving baseband.