You may find these sites of interest:

The Stewart Society

The Monarchist League

The Society of King Charles the Martyr

The Jacobite Heritage

The Ist Marquis of Montrose Society

Jacobitism in Northumberland

('The Fifteen' or Northumberland Jacobite Society have a page on the above at)

The Order of the Lion Rampant

Jacobite online discussion group
(This group exists for the exchange of information and views about all aspects of Jacobitism past and present - it is not a Society as such).

Lowestoft Porcelain

1745 Association

The Order of the Crown of Stuart

The Jacobite Studies Trust