For those not familiar with Posterous, the service offers a cut down blogging platform that focuses on ease of use. Users can email blog entries in (indeed, when it launched this was the only way to post) and Posterous pulls out the content parts and pushes it live to the web.

Despite its lack of features, or more accurately because of the lack of features, Posterous has become the “it” blogging come lifestreaming service of the 2.0 crowd. Think Blogger 2.0, but not full of emos like Tumblr is.

The new theme option offers users five set themes that they can customize colors on; not exactly open slather, but better than none at all. Users are also able to upload a logo file for each template. More details here.

It’s a step in the right direction for Posterous, and will immediately make the service more appealing to those who don’t think it’s the best thing since sliced bread yet.

The forwarding support also allows users to select which services they want their entries posted to, according to MG Seigler at Venturebeat. For example, if you wanted a picture posted to Flickr you would email flickr@posterous.com, Tumblr: tumblr@posterous.com etc.

I am a Posterous fan, and I use my Posterous blog to post interesting emails (link) that I want to share without writing a post. The addition of forwarding is a handy value add, but it doesn’t make immediate business sense. Posterous is, at its core, a hosted blogging service with a focus on ease of use via email. As a hosted blogging service its number one business goal is to build page views by encouraging people to use Posterous as a primary, or significant secondary blogging destination. By facilitating forwarding to other services, Posterous becomes an appealing intermediary to other services, but it does little to focus attention on the Posterous site. By allowing users to post to other blogs, it allows users to benefit from the easy to use Posterous posting service without ever having to visit their Posterous blog, and subsequently to share links to posted items with others. Where exactly is there a business model in that?

Of course I could be unkind and suggest that this is a content ploy with a focus on search engines. Every Posterous post forwarded to another blog is still added as an entry on Posterous, even if the blogger themselves never links to nor visits their Posterous blog. Offering this service should encourage more people to use Posterous (at least that’s what Posterous will be betting), and that can only increase the volume of content hosted, and it’s well known that the more content you have, the more traffic you usually get from Google.

Perhaps Posterous is hoping that people will switch to using their Posterous blogs after they try it as a forwarding service? Not impossible, but a risky bet.

Is Posterous grasping at straws, trying to find some way, any way of increasing their user base more rapidly? The traffic is headed in the right direction, which is why this makes even less sense from a business perspective; they would appear to be on a good thing and going well now.

The Y Combinator startup is all about ease of use. To use, send your post to post@posterous.com. That’s it, and you can include files, pictures, audio, video and text. Just remember to crop your email signature prior to sending otherwise that gets published as well. You don’t have to register either to start posting, the service generates an automatic URL for you based on your email address. If you want a custom URL, or want to edit your post, you do have to register, but the only two things you have to fill in are email address and password (and password only once).

Michele Martin at Bamboo Project notes that you could use a Posterous blog for a one-sentence professional journal, to share conference sessions as they happen, to send photos or video of an off-site event or problem or to “use it as your back-up brain.”

Off the bat it’s an appealing, well thought out service, that is insanely simple to use. Many might argue that email is dead (and it is for younger people) but this is so easy my mother could use it without any instructions. The flip side: crowded space, established players. I’ve started using Utterz and Tumblr recently to deliver some similar to what Posterous does, although Posterous doesn’t do phone call recording unfortunately.

I know I’m often happy to recommend sites for people to check out, but check this one out by sending an email to post@posterous.com so you can marvel, at least briefly, in the pure simplicity the folks behind this have come up with.