A few thoughts on blogging inspiration
Blogspire is a great suggestion tool - go sign up ;) - but when a topic doesn't come from within the process to coming up with a post is a lot more complicated. Even when the idea is yours, there is a lot that goes into coming up with a decent post.
Let me describe the two ways I write.

"my" post
When writing in a creative flurry, everything is simple (this only happens when you have plenty of free time)
- Get idea
- Become antsy to write about it
- Keep thinking about the idea while working out, under the shower, during breakfast
- Jump into a text editor
- Write like a mad man
- Breathe
- Edit a bit (30% rewrite)
- Publish
That's it. Another post is born.
This type of post feels very good to write, gets something off my mind and occasionally reaches some level of popularity on the hackernewses and such out there.
Usually these posts are flops in the traditional sense. The only post of this sort that has ever reached popularity was Living life in 25 min increments.
"not my" post
More often than not, you can't write a post the moment you think of it. You're either too busy, the idea hasn't fully formed in your head, or it just isn't the right type of idea for a particular day.

Sometimes the idea does come from outside - like when somebody from Zemanta comes up to me and goes "Hey, I think you should write about this. And if you could also make product X look good, that'd be great". Or sometimes it's a friend saying "Hey, I just launched this cool thing/solved this cool problem/did something awesome ... can you write about it?"
The idea goes on the whiteboard. Or in a moleskine. Anywhere.
Yesterday I wrote a post for Zemanta (to be published later today). Here's what the process looked like:
- "Hey, write about This Thing (tm)."
- Install product, promise to give it a try
- 3 days go by when I'm busy with other stuff
- "Hey, did you write anything yet? Just checking."
- Check out product, look at its homepage
- Go to bed thinking about the post
- Wake up, do an hour and a half_ _of research on an unknown problem domain
- Go to class
- Ruminate on the post all day
- Come up with a few key phrases and points to mention
- Start writing ... decide I still don't know what I'm writing about
- Jot down three main points, organize them in a flow
- Spend two hours writing a very crappy draft
- Watch an episode of futurama
- Rewrite the whole post in 20 minutes
- Congratulations, it is now 1:19am.
While yesterday was a particularly crappy because I haven't been getting enough off-time lately, that's pretty much what goes into writing the kind of post that reliably makes it to The Frontpage (tm).
Several rewrites from Wtf am I doing to Hey, I can publish this ... Each step also needs at least 20 minutes of slacking off before taking the next step.
But I think it's worth it.
Unfortunately, this is why the quality of my posts usually dips whenever a bunch of work is dumped in my lap. Double so if a deadline is attached to everything.