lucy24 - 8:15 pm on May 12, 2011 (gmt 0)
Even bookmarks aren't infinitely long. Mine cut out around 40. (The system uses a non-monospaced font so it probably goes by physical length. Page titles loaded down with ells and eyes could be longer.) They're also truncated in the Edit Bookmarks area.
This is a subject dear to my heart because I deal with an entity that thinks all its pages should be named in the form (details changed to protect the guilty)
"The webmasterworld archived article on the subject you're interested in"
with-- by actual count-- 31 non-unique characters before you get to the significant part of the title. So if the user has multiple pages open from the same site, all they see for any of them is "The webmasterworld archived ..." Not useful.
:: insert boilerplate about how you're dealing with humans who, almost by definition, know less about this stuff than you do ::