I have a Samsung GT i5800 and every time I turn it on, or just put a new SD card in it it says "Media search is running" (@the notifications) - How can I turn this feature OFF? Is it needed? What does it do? Android 2.1update1
The media scanner "indexes" the music, videos, images, etc on the sdcard so other apps don't have to scan the entire sdcard to know about them. another feature that uses this is the ringtones/notifications, if it does not scan, you will only be able to select the ringtones/notifications that are located on the device, not ones that are on the sdcard.
you can prevent media scanner from indexing a specific folder by creating a file called ".nomedia" in the folder you want ignored. I do not believe that this file is recursive though, so if there are sub-folders, and you dont want them scanned, you would have to create it there too.