A slight modification to the way phpMyAdmin displays 'longtext', it will not display the textarea element to the right of a row (just like any other type), but instead it will start a new row beneath it and use the entire width of the table to display the textarea element.
I found this useful for editing large chunks of HTML that were stored in a 'longtext'...
Maybe it's worth an extra config var (wideLongtext = TRUE ???).
included is a patch for 'tbl_change.php' taken from the 2.5.0 release