Here are two positions; both require U.S. citizenship.

Statistician, senior level (GS 14/15 -- $105,211-$155,500)), for the Office of Management and Budget's Statistical and Science Policy Branch (Office of Information and Regulatory Affairs).  Open: April 13 to April 27.  Job announcement #OMB-11-38-DR-MP.  Washington, DC.  For more information: 

http://jobview.usajobs.gov/GetJob.aspx?JobID=98223413&JobTitle=Statistician&brd=3876&vw=b&FedEmp=Y&FedPub=Y&x=86&y=18&jbf574=BO00&AVSDM=2011-04-13+07%3a07%3a00

Public Opinion Survey Methodologist (GS 13 -- $89,033-$115,742), for the Department of State's Office of Opinion Research.   Design and conduct international public opinion research on political, economic, social and security issues.  Also train staff in research design, sampling and statistical analysis.  Position available later this Spring.  Contact: Anna Dean, Acting Director (DeanAS@state.gov).