If you have a WordPress.com-hosted blog, you are on the road most of the time and you have a smartphone, then you should try your blog’s Post by Email feature. I have been experimenting with it for a couple of days now on my mobile blog, and the feature works great.
To activate or enable the feature is very easy. All you need is to click on “Enable Post by Email” on your blog’s control panel to output a randomly generated email address. If you think the email address is not to your liking, you can keep on re-generating an email address.
Send your post to that email address just like sending a normal email message, and voila!, your entry is automatically posted to your blog. You can see a demo of this feature on my moblog.
Warning: You need to keep that email address secret. Otherwise, anyone who knows that email address can post to your blog.
Digression: I acknowledge that WordPress.com has some applications which you can run in your mobile phone to enable you to post, edit, etc. like what you normally do in your WP dashboard. I tried that using the WordPress for Blackberry, but it does not work for me. It may work fine in your case.