4 August
An article in ArcUser on "Converting and using SDTS" solves a plaguesome problem. USGS offers online access to DEM data for all US topographic quads, but in a format (SDTS) that ArcView can't use directly. David Tarboton offers a converter

I followed Tarboton's instructions, using WinZip as he suggests, and was able to extract and then manipulate the DEMs for a couple of nearby quads. Here's the Lexington quad in two forms:

(with hillshade)

And one showing a portion of the quad with 10-foot contour intervals:

and oh jeez I can't resist adding this one of slope:

5 August
Terrain Modeling with ArcView 3D Analyst: acquiring and converting DLG data (from ArcUser)

http://miley.wlu.edu/gis/dlg.html has links to sources for large scale DLG coverage in SDTS format.

Working with USGS Map Data from Geology Department - Portland State University

(I found the requisite dlglx149 .dxf converter at http://www.cadresource.com/library/utilities.html)

As I struggle to understand this stuff I keep finding bits that look like they should be useful. One such collection is at ftp://ftp.blm.gov/pub/gis/sdts/, where Sol Katz has put together a lot of material on SDTS conversion, including various downloadable utilities.

A U.S. Fish and Wildlife page (SDTS to Shapefile Conversion Notes --see also Geographic Information Systems & Spatial Data and GIS Technical Tips pages) led me to Sol's stuff, and seems to offer other generally useful links and explanations.

But why is the needful soooo hard to find in nice neat summaries? Of course GIS isn't the only place where that question arises... Tim Loesch's tipsheets for ArcView are very useful aids along these lines. See also Mark Cederholm's tips.

THE UNOFFICIAL ARC/INFO AND ARCVIEW SYMBOL PAGE (Brian T. Sheahan) has all sorts of stuff that I'm sure will eventually be very useful

I went back to SDTS and wrote a page of instructions for importing and displaying coverage.