Twitter, Facebook, Tumblr, Identi.ca, FriendFeed, Jaiku, Blogger,
Plaxo Pulse, hi5, WordPress.com, TypePad.

 Now, which of these services can I reach straight from Posterous?

 Twitter, Facebook, LinkedIn, Tumblr, Identi.ca, FriendFeed, Jaiku,
Blogger, WordPress.com, TypePad.

 Supported by Ping.fm but not by Posterous:
LinkedIn, Plaxo Pulse, hi5.

 You know what? I think I'm starting to get it. I will probably use
both Ping.fm and Posterous, depending on device and context.

 I will keep using Ping.fm, at least for now, to share my reading from
Google Reader http://GoogleReaderShared.josschuurmans.com

 There may be a better way, perhaps even routing my shared reading
through Posterous instead of Ping.fm. I'll have to look into that some
time.

 With Posterous I can update all my current blogs and micro-blog
services, except LinkedIn, Plaxo Pulse and hi5. So, for pure status
updates, Ping.fm is preferred. But for blog posts, Posterous offers
more.

 And perhaps there is a way to route status updates to LinkedIn, Plaxo
Pulse and hi5 via one of the services supported by Posterous (e.g.
Twitter?). We'll see.