What's the process for installing a new ROM after I've just completed one? I have a HTC Incredible running 2.2, successfully used the unrevoked method and rooted it, used Titanium Backup to back up all apps and system data, and ROM manager to install and run CM7. ok, that's all done, but now i want to try Miui, is the process still the same?

What i mean is, i'd rather not reinstall all the apps as I want to try a new rom, but want to go back to CM7 if i don't like it. 

How can i try Miui, then go back to CM7 if need be??
Assuming you installed ClockworkMod Recovery via Rom Manager app (or manually), you can do the following:


Install the Appbrain and Fast Web Installer apps.  Run Appbrain, sign in with your Google account, enable the Fast Web Installer from Settings, and perform a sync.
Download the ROM installation ZIP for MIUI and place it onto your SD Card.
Reboot your phone to Recovery mode, scroll down to "backup and restore", go in, and select the "Backup" option.  This will write an image of your phone onto your SD Card.  OS, your apps and settings will be saved.
Perform a full wipe of your device from Recovery by doing a "wipe data/factory reset", "wipe cache partition", and "advanced -> Wipe Dalvik Cache".
Select "install zip from card" option, and then "choose zip from sdcard" to flash the ROM zip that you downloaded in step 2.
Optionally, flash the GApps package, and any other files (refer to the ROM's instructions.)
Once the installation is completed reboot the phone, add your Google account, and set up the system to your lining (do not download any 3rd-party apps yet.)
Open the Market app, install AppBrain and Fast Web Installer again, and sign in.
Open the Appbrain app, and enable Fast Web Installer in settings again.
While still inside the Appbrain app, go to "Manage And Sync", press the Menu button, select the "More lists.." option.  Pick the list that was created for you in step 1, and press the "Add all apps" button.  This will queue up all the missing apps that you had installed on the previous ROM.
Go back once, and tap the "Execute" button.  After verifying the permissions, tap the Install button.  This will automatically download and re-install your apps.
Once the apps are installed, configure them to your liking.
Reboot back into Recovery, perform another backup, and reboot the phone normally.
Open the ROM Manager app, and tap on "Manage and Restore Backups."  You should see a list consisting of the 2 backups you just made, sorted chronologically.
Rename the first backup to "CM7", and the second to "MIUI".


You can now easily switch from CM7 to MIUI by simply restoring the corresponding backup.  Keep in mind that if you change anything on either ROM, you will need to perform another backup so that your changes are saved.