The problem with this idea is that not every post from a friends blog is going to be suitable for your blog audience. People read your blog, probably because they like what you write about. Linking to other articles should be probably done only on a per article basis.
Why don't you start thinking and also working on what you exactly want to do on the side, and solidify your plans once you feel confident enough to make the jump? The transition does not happen overnight.
But, yes, I definitely feel you will really have a chance to learn more in a start-up, since you will essentially juggling various roles, especially in the early days.
The average user doesn't care. The success or failure of twitter will be determined by what the average person feels about it. As the appstore shows, even if you piss the developers off, new developers are not going to stop with the platform just like that.
"I'm slightly wary of a free lite version, at least at first, as people who get things for free tend to be more inclined to leave a bad review."
If someone were to take his/her time to post a review - it has to be something very extreme - either should absolutely hate the app or really love it. From the reviews I have seen on the app store, it's actually people who paid for an app and didn't like it who make a fuss..
I guess at the end of the day, there is no easy way about this. If you want leads, you need to either have a free version which will allow more people to try it and hence convert, or else put in the advertising to go for the paid customers. It's a situation that's quite similar to what I am facing too, but there is no easy way out of it. The viral loop doesn't occur always :)
You might have already thought of the following, but here is a couple of ways:
1. Offer a lite version which is free, and try marketing that and leveraging on those users to upgrade to a paid app
2. Approach iPhone app review sites and pitch the app to them for a review. (you might also consider advertising in these app review sites to begin with and to gauge the initial response)
I agree with you that blowing away your hard earned money on a big marketing spree might not be a wise decision. So, starting off with a smaller site and watching the initial reactions would give you more confidence on what to do next.
Since you are already comfortable somewhat with PHP, I suggest you take it in and work on it for a while till you understand the life cycle of a web application. I highly recommend Codeigniter framework - it does a lot of heavy lifting for you.
Taking this route will also help you realise what you like and don't like about PHP. THEN, you will be in a better position to judge if something like django or ruby on rails would suite you better.
1. Build the core product and launch a beta soon. Release early, release often. This will help you gauge the response and adapt. This will help you remove uncertainty about your own launch/idea etc.
2. You should definitely try to involve atleast one more person. As a lone founder, sometimes things can be a little dull.. However this should not mean you should force yourself to look at co-founders.. it's a tricky situation.. But, go out and talk to people, and meet more people and i'm sure you will come across people you want to work with.
3. Even if you do find someone to work along with, things can still be quite challenging for start-ups. It's something you should be prepared to face upto. This is exactly what makes the process rewarding and you should look at what you are learning from the process.
How about featuring iPad cases which are on sale on the ebay on your site (along with a affiliate link) - this should also earn you some affiliate money...