If you have started blogging with a posterous blog for convenience and now thinking of moving to a full-blown blogging platform like WordPress then they have just the right solution for you.
WordPress has just launched a Posterous import feature inside all WordPress.com dashboard. It uses the Posterous API so the import is seamless & easy. Basically all you need to do is, just login to your wordpress.com dashboard and go under Tools -> Import.
There you should see a Posterous importer option. Once you click that a form should appear, type in your Posterous host name, user name, and password in the appropriate fields and hit the Submit button.
Once the importer validates your credentials it will automatically start the import. If everything works out great then you should receive an email from WordPress saying that your import has been successful!
Why would someone want to move from Posterous?