Don R. Elsner has published a series of photographs and comments describing how he "turned an old salvaged trailer into a Trike Transport...". Details are available on Don's site.
Larry Wallace from Alabama has recently built a single-trike hangar for US$1582 only. He plans to write an article about the project and send it to the UL magazines. Until then you may read the summary of his comments posted on UltralightTrikes newsgroup and look at some pictures.