(written from a Production point of view)
Jason Collins is the actor who portrayed MACO Corporal R. Ryan in eleven episodes of Star Trek: Enterprise. As a background actor Collins received no credit for his appearances. A belt worn by him was sold off on the It's A Wrap! sale and auction on eBay as part of a MACO uniform. 
Collins appeared in several other television series. He portrayed a bartender in the 1996 Nowhere Man episode "Doppelganger", starring Bruce Greenwood, Coach Rich Andrews in four episodes of the drama series Summerland (2004-2005, alongside Star Trek performers Jay Harrington, Philip Boyd, and Serena Scott Thomas), as Ridley Cooper in three episodes of Jericho (2006-2007, with Alicia Coppola and James G. MacDonald), and more recently in two episodes of the drama series Cane (2007, with John Pyper-Ferguson, Ned Vaughn, and stuntman Craig Baxley, Jr.). He also appeared as himself in a second season episode of The Apprentice in 2004.
In 2002, Collins appeared in the thriller Ted Bundy, which also featured Star Trek performers Michael Reilly Burke, Julianna McCarthy, Bobby C. King, Jesse James Rutherford, and Tracey Walter. In 2007 he portrayed Pete Ambrosi in the television comedy Solicit Behavior, along fellow MACO actor Yuri Elvin. On the 2000 video prequel Cruel Intentions 2, Collins worked as stand-in.