President-elect Barack Obama is weighing an array of Washington insiders and outsiders, including some Republicans, for top administration posts. Obama has signaled that he will make no Cabinet-level appointments immediately, and his deliberations are tightly held by his closest aides. But that hasn't stopped speculation and recommendations to the Obama transition team.

Some are surprising, such as former Secretary of State Colin Powell as possible education secretary. Others are high-profile politicians. Yet many are little known to the general public -- and may remain so.

The following are some names often mentioned as possible appointees to top posts:

DEFENSE SECRETARY

Current Defense Secretary Robert Gates; former Navy Secretary Richard Danzig; Sen. Chuck Hagel, R-Neb., critic of Iraq war retiring from Senate; Sen. Jack Reed, D-R.I., member of Senate Armed Services Committee

TREASURY SECRETARY

Timothy Geithner, president of Federal Reserve Bank of New York; former Federal Reserve Chairman Paul Volcker; Lawrence Summers, former treasury secretary and onetime Harvard University president

SECRETARY OF STATE

Gov. Bill Richardson, D-N.M., former U.N. ambassador and energy secretary; Sen. John Kerry, D-Mass., 2004 presidential nominee; Nebraska's Hagel; Richard Holbrooke, former U.S. ambassador to the United Nations

ATTORNEY GENERAL

Eric Holder, former deputy attorney general; Arizona Gov. Janet Napolitano; Rep. Artur Davis, D-Ala., member of House Judiciary Committee; Massachusetts Gov. Deval Patrick, former assistant U.S. attorney for civil rights

ENERGY SECRETARY

Pennsylvania Gov. Edward Rendell; former Rep. Philip Sharp, D-Ind., president of Resources for the Future think tank; Kansas Gov. Kathleen Sebelius

EPA ADMINISTRATOR

Lisa P. Jackson, commissioner of New Jersey Department of Environmental Protection; Mary Nichols, head of California Air Resources Board; Kathleen McGinty, former secretary of Pennsylvania Department of Environmental Protection

HEALTH AND HUMAN SERVICES SECRETARY

Former Senate Majority Leader Tom Daschle, D-S.D.; Howard Dean, chairman of Democratic National Committee, physician, former Vermont governor; Sebelius, Kansas' governor

TRANSPORTATION SECRETARY

Jane Garvey, former head of Federal Aviation Administration; Mortimer Downey, former deputy transportation secretary; Pennsylvania's Rendell; Rep. Earl Blumenauer, D-Ore.

INTERIOR SECRETARY

Former Oregon Gov. John Kitzhaber; former Alaska Gov. Tony Knowles; Sen. Ken Salazar, D-Colo., former executive director of Colorado Natural Resources Department

HOMELAND SECURITY SECRETARY

James Lee Witt, former FEMA director; Los Angeles Police Chief Bill Bratton; former New Jersey Gov. Tom Kean, chairman of 9/11 commission; Rep. Jane Harman, D-Calif., chairwoman of Homeland Security intelligence subcommittee

NATIONAL SECURITY ADVISER

James Steinberg, former deputy national security adviser; Susan Rice, Obama campaign foreign policy aide and former assistant secretary of state for African affairs

EDUCATION SECRETARY

Colin Powell, former secretary of state, former chairman of Joint Chiefs of Staff; former North Carolina Gov. Jim Hunt; Arne Duncan, chief executive officer of Chicago public schools; Inez Tenenbaum, former South Carolina schools superintendent

AGRICULTURE SECRETARY

Tom Buis, president of National Farmers Union; former Iowa Gov. Tom Vilsack; former Rep. Charles Stenholm, D-Texas

OFFICE OF BUDGET AND MANAGEMENT DIRECTOR

Rep. John Spratt Jr., D-S.C., chairman of House Budget Committee; Gene Sperling, economic aide to President Bill Clinton; Jason Furman, Obama's campaign economic policy director

HOUSING AND URBAN DEVELOPMENT SECRETARY

Valerie Jarrett, Obama friend, chairman and CEO of Habitat Co.

LABOR SECRETARY

Rep. George Miller, D-Calif., chairman of House Education and Labor Committee; former Rep. David Bonior, member of Obama's Transition Economic Advisory Board; Andy Stern, president of Service Employees International Union

ASSOCIATED PRESS