Just got an email from Tim Conner, developer of BlogApp and BlogScript (also, he has some neat AppleScript snippets as well) with a couple of string functions he uses:

(**** Example ****)
-- this example will find the word "work" in the string 
-- "Bob went to work." and replace it with "the beach".
set myResult to snr("Bob went to work.", "work", "the beach")
display dialog myResult
--
(**** fast search and replace methods ****)
on snr(the_string, search_string, replace_string)
  return my list_to_string((my string_to_list(the_string, search_string)), replace_string)
end snr
on list_to_string(the_list, the_delim)
  my atid(the_delim)
  set the_string to (every text item of the_list) as string
  my atid("")
  return the_string
end list_to_string
on string_to_list(the_string, the_delim)
  my atid(the_delim)
  set the_list to (every text item of the_string) as list
  my atid("")
  return the_list
end string_to_list
on atid(the_delim)
  set AppleScript's text item delimiters to the_delim
end atid

Should come in handy next time I take the fork to the eye.