Ditto. But using dcraw from the CLI to convert K20 DNG to TIFF first until they release a patch for the K20. Sucks having the extra step but I just plain like LZ better than anything else.
Pentax Photo Lab for RAW conversion. I've been using (now-defunct?) Firehand.com's Ember for dust-spotting, but I caved in and got Elements tonight - haven't even loaded it. The "Spot Healing Brush" convinced me :-) It appears it may have other useful features. We'll see.
Edit: I've now converted to Elements, which seems nice so far. It is pretty handy, though I miss the exif list available with PPL.
Edit #2: Egads. I just finished processing about 1,000 PEFs shot with my K100D via Elements - no problem. Now, my new (as of today) K20D PEFs make Elements cry "wrong file type" and will not open. I tried changing the color space from sRGB and AdobeRGB and back, changed the file size (down to 6M) etc, and nothing helps. Shooting in DNG or converting to DNG via Photo Browser - those files open fine in Elements. I checked a PEF from the K100D just now and it opens fine. (I'm posting this edit in a new post so someone may see it and have an answer.)
Xnview as a viewing, selection & general processing interface, linked to PPL for RAW processing to TIFF, and linked to GIMP for heavy-duty adjustments.