The Socialist Equality Party, a national political party headquartered in Michigan, has one candidate in the November 2, 2010 election. He is D’Artagnan Collier, running for Michigan State House, district 9 in Detroit. Here is his web page. Because Michigan does not permit a political party to be ballot-qualified in just a single district (instead it must qualify for the entire state), he is on the ballot as an independent candidate.
The other parties with “Socialist” in their name, that have any candidates on the ballot in partisan races this year, are the Socialist Party, the Socialist Workers Party, and the Socialist Action Party. The Party for Socialism and Liberation is not on the ballot under its own name in any state in 2010, but some of its members are Peace & Freedom Party nominees in California this year.