Android - What to do before reformatting phone or setting back to factory state?
- If you have an SD card, I would copy its contents to a PC. That should save all of your pictures.
- Paid apps are linked to your Google account and can always be re-downloaded.
- Have you entered your contacts manually and not synced them to your Google account? If not, you don't need to back them up; they're in the "cloud", to use the common catchphrase.
- If you're rooted, you can use an app like Titanium Backup to save your applications and data, so that you don't need to redownload them (and so your settings, saved games, etc. are backed up).
Your contacts and calendar will be stored in the cloud and synced back when you re-login with the same Google Account. Also, most of your settings. Apps that you purchased will be listed in your Market Account.
I suggest you use SMS Backup or something similar to save your messages (if you wish to) to your Storage Card. GoSMS and Handcent SMS also have SMS backup/restore facility.
By default, your camera pics are stored in the DCIM folder on your storage card.
Use a backup app like Titanium Backup or MyBackup Pro to backup all the stuff first, just as an additional safety net.
NOTE: Busy right now, so haven't added links. A quick search will turn up the apps in the Market. ;-)