From LTwiki-Wiki for LTspice

Adding files for inclusion in your wiki

Email any relevant file (not copyrighted) you'd like hyperlinked to a wiki to:

Regular contributors have file upload access. Please use the above email to request upload access. You will be automatically given file upload access if you log in and contribute to the pages.

New feature February 23, 2012:

An option is added that may make your editing easier. Any image may be included directly in line with the wiki addition, without any uploading. So, for example if you see an image in the LTspice help that is on the site, all you have to do is find out the URL of that image (right clicking and looking for the link location, or looking at the HTML). Then just include that entire URL as text in the ‘Edit’ mode – and the image will appear in your work. To prove this works I included my picture in ‘About LTwiki’ at the bottom.