Selecting multiple pictures at once.
Is there a one stroke way to 'select all' photos in an album (Photostream, Camera Roll, etc.) so you don't have to tap 500 pictures to select and delete?
iPhone 5, iOS 6.1, Photostream
No. On your device, the best you can do is open the album, tap Edit, tap all the photos you want to delete, tap Delete. If you have a Mac, you can delete the camera roll photos all at once using Image Capture. You can also delete them after importing them on either a PC or Mac, as explained here: http://support.apple.com/kb/HT4083.