Mischa Barton hasn't worked in years, yet somehow she still managed to bag herself an invite to one of the most glamorous parties in Cannes last night.The amfAR AIDs gala attracted just about every big name in celebville including Jude Law, Kirsten Dunst, Naomi Campbell, Gavin Rossdale, Gwen Stefani (who looked fit), Fergie (the former Royal one, not the Black Eyed Peas one) Janet Jackson, Bar Refaeli, Karl Lagerfeld, Milla Jovovich, Jane ...