I have great ideas for stories all the time, one of which I'm working on as a novel, but several others are floating around in my head that I'm thinking about. A lot. The one I'm doing as a novel is a sort of vampire romance novel, but the romance is downplayed a lot and the main story is mainly action and investigation. As for the other ideas, I have one involving an alternate Earth where magic coexists with technology and it's set in the near future, Britain is no longer a monarchistic country and instead is ruled by a new British Empire which has similarities to Norsefire (V For Vendetta) and the real life BNP. The action follows a resistance against this Empire and follows a group of four childhood friends who, after an attack on a key location in London goes wrong (leading to the deaths of the main heads of the Resistance), end up being forced into action as the new leaders and manage to fight back against the fascist regime.
And yes, that idea did sudenly occur to me after hearing all the stuff recently about the BNP, before anyone asks or assumes. And if anyone steals the idea they'll have me to answer to, I thought it up (and no, the story is nothing like Star Wars before anyone moans), so it's my creative material. Sorry, but a guy has to protect his creative rights, after all...