A website is one of the most valuable tools to market paintings for artist of our time.
I recommend FASO to every artist who is still struggling with all the difficulties in creating and maintaining their website.
FASO is so well designed it will show your paintings professionally while still being extremely user friendly.
I feel bad for all the artists not using FASO yet.
Mailing something to yourself, otherwise known as the Poor Man's Copyright, is a long-standing myth. No case in the history of the US has been aided by PMC. Read more here: http://www.plagiarismtoday.com/2006/08/25/the-myth-of-poor-mans-copyright/
It is also false that copyright is only useful if you can afford litigation. Attorneys who specialize in this area will sometimes take cases on contingency. Also, when infringement is blatant, individuals or companies will often settle when confronted and exposed. In the past couple of years, one illustrator I know has made almost as much money pursuing infringements as she has illustrating. Her comments are here: http://dulemba.blogspot.com/2011/11/calvin-hobbes-and-copyright.html
The number of ways people can and will use others' art is amazing. People I know have found their work not only appropriated and incorporated into "new" pieces, but used unaltered on t-shirts and other types of Etsy products, used by corporations, and even claimed and included in other artists' online portfolios!