Tell me everything you know and give me a good tip for starting!
Modular Knitting
If you need to know the basics see if you can get this book from your library or buy it.
I haven’t seen this one, but it looks interesting.
There was a basic technique/pattern here on Knitting Daily.
http://www.knittingdaily.com/blogs/daily/archive/2010/06/23/modular-knitting.aspx
That is pretty cool! They make it looks so easy though! Perfectly tight seaming with no gaps! One day 
Well, this looks very interesting. I like the striped square in one of those examples, and will give it a try. Thanks for introducing me to modular knitting, psquidy, by bringing up this topic!
I have instructions for a children’s pullover somewhere. They start out with triangles, of course, then they knit the sqaures by decreasing for the square on edge and then keep that last stitch on the needle, cast on again by making stitches out of the side of the square and knit on.
The pullover had kind of a patched and gypsy style look, I was not sooo keen on. but if you use the right colors and work neatly it can be very nice.
If you need more instruction I can look up the technique from the magazine somewhere. let me know.