Fooplot.com is a nice graphing calculator that uses the browser’s native SVG (in Firefox and Opera) or VML (in IE) to display function graphs. FooPlot can save to EPS, PDF, PNG, or SVG (though it seems to generate a broken SVG 1.1 DTD, which stops Squiggle in its tracks; Inkscape continues past the error). A nice touch is that you can embed the function to be graphed directly in the URL (http://fooplot.com/x^2+2*x+1).

There is another SVG-based graphing calculator, but it’s a Firefox extension (which may or may not be more convenient, depending on your location and browser of choice).