Mounting and Unmounting of Memory Card just by touch?
NOTE: I am on Samsung Galaxy S2, Android 4.0.3

Elixir for Android has an "sd mount toggle" feature. It could unmount a removable card (/mnt/sdcard/external_sd), but not (/mnt/sdcard). I could not get it to mount by clicking the toggle again, but a restart [toggle also available] will mount the removable card. This is probably a bug with Elixir; and I will try to contact the developer.