Memory cards aren’t very exciting, but they are pretty important, so it’s good news for mobile users that Sony has doubled the capacity of its Memory Stick Micro (M2) cards to 8GB.

Sony claims the 8GB card will allow mobile device users to store over 5,000 fine quality five megapixel photos, over 2000 MP3 songs, or over 88 hours of high quality MPEG4 video…