I'm not going to suggest any particular issue to contact officials and leadership about because they are all urgent matters.
This is a resource thread, add to it and keep it kicked. If you've contacted officials keep doing so-if you haven't--begin doing so.
Most of these links are easy to navigate, some are intended for one function yet have other useful links as well.
Congress.org
http://www.congress.org/congressorg/home/US House of Representatives
http://www.house.gov/Representatives Offices (suggested for writing-also has many e-mail, phone and fax numbers)
http://www.house.gov/house/MemberWWW_by_State.shtmlHouse Leadership Offices
http://www.house.gov/house/orgs_pub_hse_ldr_www.shtmlUS Senate
http://www.senate.gov/US Senators Offices
http://www.senate.gov/general/contact_information/senators_cfm.cfmSome US Congress DC office direct phone numbers
Hon. Nancy Pelosi, Speaker of The House
(202) 225-5745
Hon. Steny Hoyer, House Majority Leader
(202) 225-4300
Hon. John Conyers, Chairman of The House Judiciary Committee
(202) 225-5126, (202) 225-0072
Hon. Jerrold Nadler, a member of The House Judiciary Committee and Chair of the Subcommittee On The Constitution, Civil Rights and Civil Liberties
(202) 225-6923
Hon. Dennis Kucinich, who introduced HR 333 the impeachment of Richard B. Cheney-now HR 799 pending in The House Judiciary Committee
(202) 225-5745
TOLL FREE HOUSE SWITCHBOARD NUMBERS
1-800-862-5530
1-800-828-0498
1-800-614-2803
1-866-340-9281
1-866-338-1015
1-866-220-0044
DU Activist HQ and Research Forum also has some useful resources, especially for local and national media.
It's urgent for all citizens to contact these officials and leaders. Add other resources to this thread and keep it kicked.