Hi there, lost my phone. How can I access my photos on iCloud ? Please help.

If you set up iCloud on your computer and enable photo stream, you can access photo stream photos from the last 30 days (see http://www.apple.com/icloud/). Older photo stream photos are no longer in iCloud.

Your backup would contain camera roll photos but you would have to restore the backup to another iPhone (or iPod Touch) in order to recover them. If your backup is in iCloud, be aware that Apple will delete it after 180 days of inactivity.

The backup is stored on a hard drive on Apple's iCloud servers. When you delete the backup, it is deleted from the hard drive; and there isn't a "recycle bin" or "trash can" you can use to recover it from iCloud like you have on your computer.