xlockmore-gl 1:5.27-1 (i386 binary) in ubuntu lucid

 xlock locks the X server till the user enters his/her password at the
 keyboard. While xlock is running, all new server connections are
 refused. The mouse cursor is turned off. The screen is blanked and a
 changing pattern is put on the screen. If a key or a mouse button is
 pressed then the user is prompted for the password of the user who
 started xlock.
 .
 This version is built with additional OpenGL and XPM modes. The
 companion package xlockmore does not contain them. This is the only
 difference between the two packages.