I'm looking for the name of a film that came out within the last few
years. I'm not sure if it was released in theaters or if it was made
for t.v. I don't remember much about the actors, but the plot involved
a futuristic/time travel scenario, I think based in Los Angeles. There
are plot flashbacks between modern urban life and scenes in either the
1920s or 1950s. This creates deja vu type scenarios. The key aspect of
the movie is that nothing exists beyond the city, and so the movie
climaxes with this guy driving out to the edge of the city to find out
what's there. He looks out literally on the edge of the world. That's
all I remember. If you can get me the name of the film, I'll pay the
money.

Dear johnwr,

The movie you have in mind is "The Thirteenth Floor" from 1999,
starring Craig Bierko, Gretchen Mol and Armin Mueller-Stahl.
In the center of the plot there is a virtual reality 1937 Los Angeles,
a perfect simulation, created in a 1999 VR laboratory. Involved in a
crime, one of the programmers is wandering between the two locations
on the search for clues, while the beings in VR-Los Angeles are
beginning to discover the strange limits and borders of their world.

In a synopsis by Robert Roten, which is listed among the sources
below, there is a paragraph illustrating the 'drive to the edge of the
world' you mentioned:
"His quest for knowledge, driven by the need to clear his name of the
murder charge, leads down a dark path to a terrifying and
mind-boggling discovery. At one point, a character in 1937 Los Angeles
drives down a deserted road and comes to the end of the world, the
very limits of his computer-generated reality. He is only a computer
program, electrons flowing through circuits. The knowledge drives him
mad."

The movie is available, for example, from Amazon.com:

VHS video ($ 9.95): http://www.amazon.com/exec/obidos/ASIN/0767819446/qid=1027887393/sr=1-1/ref=sr_1_1/002-0741767-1472062

DVD ($ 17.96): http://www.amazon.com/exec/obidos/ASIN/0767821629/ref=ed_oe_dvd/002-0741767-1472062

Additional links:

The Thirteenth Floor, official movie website, by Sony Pictures
Entertainment, 1999
http://www.thethirteenthfloor.com/

Laramie Movie Scope: The Thirteenth Floor, movie review by Robert
Roten, 1999
http://www.lariat.org/AtTheMovies/13thfloor.html

The Thirteenth Floor, plot synopsis, author and year unknown
http://members.fortunecity.com/johnb53/t/ThirteenthFloor.htm

Search terms used:
"sf movie" "los angeles" reality:
://www.google.de/search?hl=de&ie=UTF-8&oe=UTF-8&newwindow=1&q=%22sf+movie%22+%22los+angeles%22+reality&meta=
"the thirteenth floor":
://www.google.de/search?hl=de&ie=UTF-8&oe=UTF-8&newwindow=1&q=%22the+thirteenth+floor%22&meta=
"the thirteenth floor" limits:
://www.google.de/search?hl=de&ie=UTF-8&oe=UTF-8&newwindow=1&q=%22the+thirteenth+floor%22+limits&meta=
"the thirteenth floor" limits end:
://www.google.de/search?hl=de&ie=UTF-8&oe=UTF-8&newwindow=1&q=%22the+thirteenth+floor%22+limits+end&meta=

Hope this helps!
Regards,
Scriptor

an excellent answer, exactly what I was looking for.

When reading the description, I immediately recognized it as "The
Thirteenth Floor," since I have watched it about a year ago. 
Surprising ending, but not so surprising nonetheless.