I recently purchased a BOB Ibex Trailer. It has been very good, but I swapped out the supplied tyre and inner tube for more durable expedition grade ones (Schwalbe Marathon etc). The 4130 cromoly steel frame has reasonable well engineered construction. It now works in conjunction with a rather retro looking Mountain bicycle built from a frame (A Columbus Nivachrome Silver soldered fillet design) I welded together back in the early 1990s (so no energy sucking suspension front or rear). It even has some retro Cinelli Spinaci Trekking Bar Extensions , which are basically triathlon bars for Mountain bike bars. Decent quality bicycle parts are now rather shockingly expensive (so are the Bicylces), so I decided to go retro where some bargains could be had (New Old Stock) to keep the costs down. Many of the retro bicycle parts are actually engineered more robustly than the modern gear.

http://www.bobgear.com/ibex

It allows for more carry weight than panniers/racks and will attach much more quickly to most mountain, road and cyclo cross bicycles. I just need to remove the rear wheel skewer and use the BOB one.

http://www.youtube.com/watch?v=ND0SERkAAtw

The suspension swing arm for the trailer wheel works really quite well. It even has 4 water bottle mounts.