Internet Explorer 8 supported
After far to much trouble tracking down weird JavaScript errors and testing using an IE8 virtual machine, GPSLog Labs has been made IE8 compatible. If you're using IE8 and still notice any issues with the graphs or maps, please let me know.
Update: Ok, so the graphs don't work so well in IE. If there are a lot of points in a log (more than about an hour's worth), the graph may not draw properly. This is a bug in the library used to provide <canvas> support for IE. If you select a smaller range on the graph to zoom in then it'll show the graph data.