Survey Documentation and Analysis (SDA) is a web based interface that allows access and analysis of data. The data can be accessed from IPUMS or from  the Inter-university Consortium for Political and Social Research (ICPSR).
SDA allows you to:

• Browse the codebook describing a dataset
• Calculate frequencies or crosstabulation (with charts)
• Do comparison of means
• Calculate a correlation matrix
• Compare correlations
• Perform multiple regression
• Perform logit/probit regression
• List values of individual cases
• Recode variables (into public work area)
• Compute a new variable
• List/delete derived variables
• Download a customized subset

SDA allows you to analyze data at a level appropriate to your level of experience. SDA can only analyze datasets that reside on an SDA server. If you would like to test drive SDA, or to see if SDA is useful for your research check out their General Information page.