All of the above, plus building an online presence in your area of choice. It is both a good way to make weak ties that turn into strong ties, and a good way for folks to find you when you're not actively networking.
Blogging and community participation (HN, etc) is my best source of consulting leads next to personal recommendations (and it is often a friendcatcher which caught the person doing the recommending).
Blogging and community participation (HN, etc) is my best source of consulting leads next to personal recommendations (and it is often a friendcatcher which caught the person doing the recommending).