I recently found these yoga pants in a Victoria's Secret "Pink" store and was tickled pink (pardon my lame play on words) to discover that 1) they actually carried the long (35" inseam) size in the store, and 2) the pants fit great, were comfy and affordable ($29.95). I wasn't too crazy about all the psychedelic colors, so I just opted for the plain black and white design.
VS has a fair amount of long pants on its site. Check out the full list here. Unfortunately, some of the tall sizes only come in 34" inseam, but some of the dress pants (such as the Kate bootcut and the Christie flare) and the jeans come in 36". Hooray!