At last week's SVG Working Group meeting we discussed textPath method="stretch". This value tells the renderer to distort the text along a path so it better fills up the space between glyphs. Only Opera seems to have implemented this and it does it by making a "trapezoid" like distortion. The actual method for distorting the glyphs is not defined in the spec. Israel Eisenberg has proposed that glyphs be distorted so that horizontal lines are "offset mapped" to (bent to follow the curve of) the path and he provided some compelling examples.
I mentioned that Inkscape has some general path distortion functionality. The question was raised as to how the distortions are done so I've prepared a web page to demonstrate some of the ways one can distort paths in Inkscape. You can find the page at:
The methods were designed for generic paths and have a few drawbacks when applied to text. The drawback include using the bounding box rather than the base-line and ascent in calculating the distortion, not always preserving straight vertical lines as straight lines, and the obvious one, that the semantic content of the text is lost. I imagine, someone versed in the LPE code could easily remedy the first two.