High Roads
Here are some I know of; other contributions or corrections welcome. I have preferred HERO/4x4xplore's own GPS readings to map heights. I have tried to show all known roads and named (not necessarily motorable) passes of 5,000m or more in Asia, all motorable roads (including 4x4 trails) of 12,000ft or more in the USA, all roads of 3,000m or more in Africa, and all roads of 2,500m or more in Europe, plus other interesting roads including the 'highest' in as many different countries as I know.

Main source maps: Delorme USA state atlases, especially Colorado 2nd edition (1995) - this has an interesting list of passes in that state, no fewer than 38 are over 10,000ft!; Nelles Northern India 2005 edn; Gizi (Hungary) India 2004 edn; GeoCenter (RV Verlag) China 2005 edn; Ordnance Survey Ireland and Northern Ireland 1:50K series; Lesotho Government 1:250K map 1994 ('L-OS'); and Michelin road atlases France 1:200k and Europe (various scales).

Figures in brackets are from secondary sources, or are my conversions from metres to feet or vice versa (using conversion website). Many map heights are suspect, and differ from each other; some are clearly rounded; but I regard Michelin as pretty reliable.

I have personally traversed passes/roads marked with an asterisk, and our organisation HERO/4x4xplore (see www.hero.org.uk or www.4x4xplore.com) have organised motor rallies across those marked with two asterisks.
Sadly the greatest concentration of ultra-high passes is in one of the world's major border flashpoint areas, Kashmir and the Himalaya, where India, Pakistan, China and Afghanistan come together, and it may be a long time before we are free to roam them with our cameras and GPS.

For an interesting list of climbs, see http://www-cgrl.cs.mcgill.ca/~luc/climbs.htm; for a terrific cycling website on European passes, see http://www.aukadia.net/alps/. For a helpful list of US passes and scenic roads, see http://freespace.virgin.net/john.cletheroe/usa_can/driving/mountain.htm.

A useful list of Pakistani passes is at http://www.angelfire.com/al/badela/Passes.html