So you decided to go ahead and root your Android device, now what?
You might want to install a useful utility called ROM Manager to help in managing your rooted device. ROM Manager does two basic things: It installs ClockworkMod Recovery to back up and/or recover your phone's system, and it downloads and installs custom ROMs (versions of Android).
You can find tons of custom ROMs to choose from, including the popular CyanogenMod, Lithium Mod, cvpcs, Ihtfp69, JagerRom, Virtuous, Uncommon Sense, MIUI and Berzerker, just to name a few. Each ROM brings something new to traditional Android. Once you have downloaded a ROM, you can use ROM Manager to install it on your device. Since the ROMs save to your SD Card, you can switch back and forth depending on your preference.
You can also use ROM Manager to back up and restore your ROM. I used ROM Manager to back up my HTC Droid Incredible factory ROM, and then to download and install the CyanogenMod 6 ROM. The whole process went smoothly, without a hitch. Since CyanogenMod doesn't include Google Apps, I also used ROM Manager to download and install them.
So far I'm very pleased with the results, for example, the CyanogenMod soft keyboard is much more accurate than the factory one. But it's good to know that I can easily revert to the factory ROM if necessary.
ROM Manager includes utilities to partition your SD Card and 'Fix [file system] Permissions'.
If you want even more options, ROM Manager Premium ($5) also offers update checking, over-the-air updates for supported ROMs, an 'Install from QR Code' feature, and a larger catalogue of custom ROMS. That seems like a very reasonable price to support the development of such a powerful tool.
ROM manager makes switching between Android ROMs simple and quick. One click recovery image installation and cache or data wiping make simple maintenance operations the work of a few seconds. If you intend to use custom images on your phone, you need this app.