Summer Opportunities
This page constitutes an overview of different opportunities for physics undergraduates.
Jobs
Many students do not want to, or can't afford the luxury of doing research over the summer. It is important to remember that unspecialized job experience can still be valuable and absolutely does not preclude the possibility of Graduate School. Furthermore you will be guaranteed steady income. There are many campus resources if you seek this kind of work. Some of the most common websites include Glassdoor, LinkedIn, etc.
General Research
Email a professor at any professor (politely) asking to work for them! They may even pay you! Generally its wise to send along your resume/CV and if you would be willing to work full time etc. This technique doesn't lend itself to being part of a program so there aren't very many more restrictions or constraints beyond this. Most students get summer research this way.
REU
Insert REU stuff
SURF
Insert Surf stuff