This subject came up when I was reading alt.usage.english many years ago.
The original thread was spawned by the juvenile riddle to which the correct answer is:


Why? Because there's a mile between the first and last letters.

A prompt response from one poster was that Beleaguered must therefore be a longer word
since a league is three miles.

That was when the thread took off:
"That doesn't count because it requires you to add too many letters."
"laud is longer, because the AU it contains is an astronomical unit!"
"In that case glyph contains a light year!"
"Abbreviations don't count!"
"She spelt Beleagered wrong!"
and so on and so forth.