That tutorial has some great techniques in it, but I just noticed your post and thought I'd caution folks that Brown's tutorial has a glaring error in it (as of about 2 weeks ago.) Ie., he says that using the extracted mask is identical to using the original extract result. This is not true.
When you use the extract filter in Photoshop, it does two things: 1) reduces opacity of background pixels according to how closely they match the background color, 2) removes color components derived from the background colors and replaces them with foreground color. In extracting a mask, Brown eliminates #2, thus leaving behind the color halos that plague the simple masking method and missing out on one of the great features of the extract filter. In his tutorial, he goes on to adjust the mask to erode the halo, but this necessarily over-erodes the foreground as well. The distinction becomes more noticeable as the background becomes more different from the original.
For the magic extractor tool (not the same as extract filter) in Photoshop Elements 4, what he says would be correct. Adobe has left out this critical feature of color decontamination from the magic extractor.
Other than that, the tutorial has great pointers on how to use alpha channels with the extract filter and, of course, is very entertaining due to his hilariously enthusiastic tone.