There are probably very few cases for which this is technically a good idea (trying to be a featured author on JunkCharts might very well be one of those reasons). Nonetheless, there are at least a couple of requests for this floating around on stackoverflow; here and here for example. I struggled to find any satisfactory solutions that were in current working order (though perhaps my Google-fu has failed me).
Jonathan is rather against this idea, and it does seem like the answer is a hack. I suppose the real answer is “sometimes an image isn’t worth a thousand words.”