The top chart above shows initial jobless claims (4-week moving average) and the civilian labor force from 1987 to July 2008. The labor force has increased by 30% since 1987, so the frequent comparisons of today's jobless claims of around 419,500 (4-week moving average, see today's BLS report) to previous periods and previous recessions is potentially misleading (thanks to Dennis Gartman for reporting this).
The bottom graph above (click to enlarge) shows initial jobless claims as a percent of the labor force, to adjust for the increase over time in the population and labor force. July's 0.248% level (383,375 average weekly claims / 154,603,000 labor force) is below the 0.27% to 0.33% range of the last recession in 2001, and way below the 0.30% to 0.40% of the 1990-1991 recession.
Further, today's level of 0.248% is still below the .257% average since 1987. Perhaps the BLS should develop a new measure of unemployment claims, adjusted for the size of the labor force, just like the unemployment rate gets adjusted and reported reported (as a percent of the labor force).