Photo steam photos from the last 30 days are still in iCloud and could be accessed by signing into your iCloud account on your Mac or a replacement iOS device and enabling my photo stream. Your Mac would have to be running OS X 10.7.5 or higher with either iPhoto '11 9.2.2 or higher, or Aperture 3.2.3 or higher in order to do this.
If you back up your phone to iCloud, the backup would include your camera roll photos (unless you excluded them in your settings). These could be recovered by restoring the backup to a replacement iPhone (or iPod touch). Note: iCloud backups will be deleted after 180 days of inactivity.