TESS (Time-Sharing Experiments for the Social Sciences) is a great resource for faculty and graduate students to conduct experimental research with a generalizable population of adults for free. Yes, you read correctly, FOR FREE!
Funded by the National Science Foundation, you can submit brief five page proposals to conduct a study, they are peer-reviewed, and if approved, you can field the study at no cost to you. Great way to replicate experiments with adults, collect a larger data set of respondents with more heterogeneity of traits/individual differences, etc.
You can find more infomation about TESS at http://www.tessexperiments.org and how to submit proposals at http://www.tessexperiments.org./howtosubmit.html
In addition, TESS has a special competition for young investigators - i.e. graduate students - that is meant to allow graduate students to field large scale studies. You can find more information at http://www.tessexperiments.org/yic.html.
If you have a any questions about TESS, please feel free to email me as I am an Associate PI for the program and reviewer of proposals at firstname.lastname@example.org.