A nonsense phrase that, to the best of my knowledge, was created by Terry Pratchett. It has slowly been spreading throughout populations of nonsense lovers everywhere.
"Millennium hand and shrimp" has appeared in both Pratchett's Discworld series, where it is muttered by Foul Ole Ron, a rather marginal member of the Beggars' Guild, and in his Johnny Maxwell books, where it is said by Mrs. Tachyon, the apparently schizophrenic and omnipresent bag lady. Due to Foul Ole Ron's influence, it often appears as "Buggrit, millennium hand and shrimp".
Google records 518 uses, 63 of which are accompanied by Pratchett's name, and 310 of which are part of Ken Coar's signature*. 145 are just people being weird. There are also 192 misspellings (that I have found), the most common being "Millenium Hand and Shrimp", at 185 (only 114 once the Pratchett's and the http://Apache-Server.Com/'s are taken out).
Insofar as this has any real meaning, it might, sometimes, be used as an expression of disgust or irreverence. More likely, it expresses the idea that the speaker is in a Weird and Crazy mood.
* Here is the entire signature, for those who must know.
Ken Coar, Sanagendamgagwedweinini http://Golux.Com/coar/
Author, developer, opinionist http://Apache-Server.Com/
"Millennium hand and shrimp!"