I'm having a bit of a brain fart here and failing at programming 101...

I have an array (say somewhere between 30 and 100 items), and I want to step through it gradually, over the course or a minute or two. That is, I will increment a pointer variable (v) for myArray[v], so that things looking up a value in myArray will see the same values until V is moved.

I want to be able to set a specific time (accurate within a few seconds) for processing to step through the array (increase v). Since v obviously must be an integer (and for my purposes i cannot interpolate, and don't want to), how do I figure out how many frames to wait between increments?

something like
Code:

framesBetweenIncrement = (timeInSeconds*frameRate)/lengthOfArray;  

seems obvious, but it always runs way quicker than desired.

Any hints?

frameRate isn't really useful for timing, because it's always changing.  Even if you set the frameRate using frameRate( n ), you're just setting the maximum.  You want millis(), which returns the milliseconds the program's been running.
So,

if (millis() - lastCheck >= timeInterval){
 doStuff;
 lastCheck = millis();
}

--Ben