At the moment (Sept. 3, 2009), Wikipedia has the familiar lyrics to Loch Lomond - those attributed above and often elsewhere to Lady Scott - as being the words to Andrew Lang's poem.

"Andrew Lang

About 1876, the Scottish poet and folklorist Andrew Lang wrote a poem based on the song titled "The Bonnie Banks o' Loch Lomond". The title sometimes has the date "1746" appended[3]--the year of the defeat of Bonnie Prince Charlie's rebellion and the hanging of some of his captured supporters. Lang's poem begins:
There's an ending o' the dance, and fair Morag's safe in France,
And the Clans they hae paid the lawing, ..."

It goes on to give the lyrics we see in the DT for "Loch Lomond" (no number).

So I'm still trying to figure out who wrote those most familiar words to "Loch Lomond" and where the tune came from.