I am looking for a movie title.  I have researched many movie
databases and not found it.  The story line is about a couple with at
least one child, who either own or rent a home on a rocky island, or a
rocky coast. It could be in the northwest.
Their next door neighbors, a couple who visit irregularly, appear
mysterious at first, but then look like suspects in a crime.  The main
couple sneak into the neighbors house at one point to look around for
evidence.  Please include your research methods.  I could not find a
way to search by plot. It is not the movie Pacific Heights.

Hi;

Great question! (Of course, I would say that since the movie title
leaped immediately to mind.)

I am pretty sure that the movie you are looking for is Another
Stakeout (1993, Kouf/Bigelow Productions / 	Touchstone Pictures.) It
is a sequel to  - wait for this - Stakeout.

In Another Stakeout , cops Richard Dreyfus and  Emilio Estevez are
joined by DA's investigator Rosie O'Donnel to stake out Dennis Farina
and Marcia Strassman	. A real  movie reviewer would call what follows
a "series of comic misadventures."

Another Stakeout was directed by John Badham. That point  happened to
be the thing that triggered my memory - I knew the Another Stakeout
was directed by the same guy who did Bird on a Wire, which was filmed
near where I live. (I should have recognized - so was Another
Stakeout. The locations are near Vancouver, BC.)

To find the movie, I used the Internet Movie Database
(http://www.imdb.com), a resource I use quite often. Since the IMDB is
very comprehensive and detailed, and everything is cross linked, I
often use it to find movies. Starting with a single piece of
information, such as "The second fiddle, whose name I cannot remember,
was also in a movie with somebody whose name I can remember..." The
IMDB can search by plot synopsis, but I have not been very successful
using that feature.

It is also a treasure trove of trivai with which to annoy your friends
such as this nugget:

"Richard Dreyfuss, as Chris, while standing in front of a line of
drying panties, repeats the line "And I don't like the panties hanging
on the rod" that he said in his Oscar-winning role of Elliott in The
Goodbye Girl ."

My research method in this case  was to look up Bird on a Wire ( a
movie I can always remember, since my wife adores Mel Gibson and hates
Goldie Hawn) bringing up a full listing of details about that movie. I
thought the director was the connection to the movie I wanted, so I
then clicked on the director's name. Due to the way the IMDB is set
up, that got me a list of all of his films. From there, Another
Stakeout was easy to find.

Thanks for giving me an excuse to wander through the IMDB! I've found
a couple of movies to rent for the weekend - it looks like it'll be a
Richard Dreyfus Film Festival! (At least Close Encounters and 
Jaws...)

So long from the cheap seats!
daveslipp-ga

Daveslipp...you "nailed it"!  That is exactly the movie!  I went to
you link for indb & looked at the trailer.  I'm so impressed.  Hope my
video store has it in stock.  Thanks & regards.

That sounds like the movie.  The only thing I would add is that it
does match your description of "Northwest" - the movie was filmed in
Puget Sound, Washington just outside of Seattle.  To refresh your mind
about this movie check out the 20 second movie clip found at
http://www.hampstead.com.au/mb/indexfive.html (Mercedes in the
Movies).

It could also be Arlington Road:

"Widowed when his FBI agent wife is killed in an FBI anti-terrorist
operation gone wrong, a college professor (Bridges) becomes
increasingly obsessed with the culture and sub-society of these
dangerous groups. The arrival of new neighbors (Robbins, Cusack),
gives him new spirit, as they are gregarious and friendly, with two
children (Gamble, Green) that his son (Clark) can be friends with. He
is even beginning to see another woman (Davis). However, he begins to
suspect something is odd about the neighbors, something about the way
they don't want him to see certain parts of the house, or a set of
blueprints they have there. Are his neighbors terrorists... or is the
stress of losing his wife merely driving him past the point of
paranoia?"

From imdb.com

Arlington Road misses the "rocky coast" parameter.

indicted...It was Another Stakeout!  Thanks for the link to the
Mercedes site.  I tried to view it, but it wasn't running the clip, or
I didn't know how to open it.  Pretty interesting site nonetheless.
BJK
The Another Stakeout Fan

jeeagle
Arlington Road is not the movie I had in mind, albeit an excellent
movie.  It was Another Stakeout (imdb is a treasure trove of info). 
If you haven't seen it, I of course would recommend it.  Hope you like
it.  Thanks for your input.
BJK