The acronym means: What's On Your Workdesk? Wednesday
The number: is the number of Wednesdays that we've been doing this.
It started because: I'm nosey and wanted to see what other people have got and what other people do at their desks whilst I'm busy procrastinating.
You can join by: uploading a photo to your blog, using the acronym in the title of your blog post and linking your blog on the Mr Linky under the appropriate Wednesday post. You don't need permission and there's no commitment, join in on any Wednesday that you have a mind to!
There is: apparently, a competition for the number one link.
There are: a lot of people joining in. Reciprocity is the name of the game, then random visiting if you still want to see more.
It helps: if you turn off word verification. Oh man, it helps.
Rules?: There aren't any rules per se, but let me advise you about using WOYWW to advertise. Linking to every other product is a turn off, it makes reading difficult and really dilutes the impact of your article.
Linking your latest post (and not a desk related Wednesday post) to WOYWW will cause the quickest click away...visitors from this MEME want to see your desk or at least what you're currently crafting....comments, readers etc happen that way. I recommend you come back the next day and compare your hit rate or comments to those of real WOYWWers. Then you'll understand. And anyway, this particular weekly thing - it's kinda not about the hit rate, it's about the community you discover.