PhD visit programs

Many universities invite prospective PhD applicants to campus in the fall to meet faculty and graduate students and learn how to apply. Most pay for travel, a hotel and meals, and some waive the application fee. Most fly-ins take applications in July and August, so apply the summer before senior year.
Every visit program is in the PhD opportunities list. Open now: Notre Dame's Our Futures Weekend (juniors, due Nov 15) and Princeton's P3 (due Mar 15).
No visit? You can still get a fee waiver.
Yale waives its fee for Pell Grant recipients, and UChicago Social Sciences waives it for undergrads on need-based aid. See Applying for more.