I am not sure if there are enough people that care/realize the importance of this. I personally do.
Fortunately for me I had great English teachers in high school that designed their classes around effective communication rather than fancy writing. I still drop them an email every now and then to get their advice on how I could communicate a given idea more effectively.
A service that crawls a given URL and reports spelling or grammar mistakes would be relatively easy. The 'lynx' and 'spell' utilities inherent in most Linux distributions would suffice for the basics.
I think the service would be better marketed as a last line of defense against linguistic embarrasment. If the 'service' found a typo, punctuation (that would be a little harder) or grammar error on a given URL it could simply e-mail a designated contact, show the error in context and suggestions to correct it.
This would be useful only in situations where ajax based "as you type" correction (or more traditional regex post-posting) is not possible, or if a site blindly imported harvested content from other sources without human checking for such errors.
Given the ease of which this could be developed, I say .. go for it.
1. How many people would want this? It seems like the number of people who take their blogs seriously enough to be willing to pay for this is maybe a thousand.
2. I don't see how this can scale. Unless you're thinking of AI, or some sort of peer-to-peer network, then you're selling a skilled-labor-intensive service, not a product. You might be able to form a profitable small business, but I wouldn't call it a startup.
It doesn't need to be as purpose-specific as the title suggests. Blogs are a medium of communication; there are many possible media.
Consider this interaction. A: this rose is green. B: roses are not green. C: (so the rose is not green!). C: actually, it's not a rose, it's a leaf.
This can occur in a blog, in a chatroom, and more importantly, it occurs in everyday life. Proofreading, fact-checking and such is a streamlined application of this self-correction process (e.g., of the ABC system above), applied to written material.
While we are a far way off from AI that can do this on the fly, the processes certainly is extendible, and should be extended. It's how ideas evolve.
This the type of thing that is doomed to fail. And it _should_ fail, because filtering peoples thoughts through a machine will lead to everyone speaking the same online, when in real life people do not speak that way!
Blogs are real people with no editors. If you want correct grammar, and fact checked posts, read a newspaper.
The service isn't actually trivial. And I don't know if amichail has anything specific in mind, but improving the quality of a writing is not as simple as following stylistic guidelines.
First, battling over grammar and word choice shows that there are usually multiple interpretations and construction methods for a single utterance.
Second, grammar and word preferences change over time. While this makes a case for writing fashionably, it also means that really good writings are valued for content; good content can be expressed without strict adherence to guidelines. Rap, for example. It makes no sense to proofread rap.
In any case, there are no absolute rules for language use. This point is stronger when you have a large readership, and even stronger, when your readership has the ability to talk directly to the author, and perhaps even contribute.
The challenge is to be able to accomodate a huge number of these copy editors, who come and go as they please, shout or whisper their preferences, and somehow make the end useful and actually better.
Fortunately for me I had great English teachers in high school that designed their classes around effective communication rather than fancy writing. I still drop them an email every now and then to get their advice on how I could communicate a given idea more effectively.
Other than that I love Orwell's paper on English(http://www.mtholyoke.edu/acad/intrel/orwell46.htm) He makes great points that every blogger can learn from.
-Zaid