Overlaying mass data points as a png

[PStust]

I have a huge amount of GPS data (100k+ lat lng points for each user) that I want to display over a google map. I have made a php script that will reduce that data to a png image and apply it to my google map perfectly (I can automatically generate and cache these images). The issue I have is that if the tracked unit has travelled a large distance from a central point, the size (width, height) of the image is huge. It seems that google maps cannot handle the size of the image. It causes crashes sometimes and poor performance and usability. I was thinking the solution was to tile the images like Google maps does.

How can I achieve this with the google maps v3 API and javascript (with JQuery). If I have to download each buffered image separately, how do i cache the images user side and apply them to the map during scrolling/zooming? 

Is there another, better approach?