I'm sorry Facebook but your ad targeting systems are wildly inaccurate and reduce that valuable screen estate to the right hand side of my browser window to irrelevant line noise. Google's and Yahoo's ad targeting is pretty darn good but looking at Facebook right now offers me:

• Omniture Research; which Obama used, apparently.
• Free laptop from Vodafone Business; I'm not self employed so a business tariff is a non starter.
• Everyone plays Mafia Wars; except me and most of my friends.

I've never run or hosted my own search engine. I've run and hosted web servers, mail servers, proxy servers and caching servers (I'm even contemplating running my own URL shortener), but never a search engine. There was a time when I ran an enterprise instance of Alta Vista back when I coded for a living and was part of the team building Factiva.com, but that doesn't count.

If I had have run my own search engine I would have known just how important canonical URLs are and that having multiple copies of the same content hosted on different domains would cause search engines to penalise you and loose search engine ranking, fast.

I've never been a massive fan of Crowded House but 1991's Four Seasons in One Day could have been written with this weekend's weather in mind. We started with Winter (cold, wet, miserably damp), followed by Spring (heavy showers, glorious sunshine and the odd rainbow or two), followed by Summer (clear blue skies).

Last night I was at LBi in the old Truman Brewery on London's Brick Lane for Mashup's Location ... It's Moving On. I've spoken at a Mashup event once or twice before but this time the organising team threw caution to the wind and asked me to chair the panel discussion.

Prior to kicking the panel discussion off, I attempted to gently suggest some topics to my fellow panelists that we might want to discuss.

We started off with a quick review of my Theory of Stuff and how it applies to deriving value from location and location data and briefly visited Gartner's hype curve which puts location based services on the so called Plateau of Productivity. This is a good thing apparently. I then presented the panel with a series of  "yes, but" style trade offs to mull over.

• Smartphones vs. other phones; 21% of phones expected to have GPS by EOY 2009, but what about the other 79% without?
• LBS and LBMS vs. other (older) location systems (APIs and so on); LBS and LBS apps get all the publicity but what about key location APIs, platforms and services?
• "where's my friends" vs. creating value and creating data; "where's my friends" doesn't work as a (sole) business proposition but creating value added data does -- FourSquare and Gowalla are creating geotagged local business listings from check ins.
• "where's my business" vs. location based advertising; Tesco and Starbucks are the latest companies to launch apps to drive customers to their premises, but what's needed to drive location based ads?
• "where I think you are" vs. "where I say I am"; For a user, being able to be their own source of truth is imperative, but how can you reconcile this with your business needs?
• "where you are" vs. "where you've been"; (AKA tracking vs. privacy) How to walk the fine line between providing enhanced relevance via a user's location and being accused of tracking them.

I recently wrote about echoecho, an SMS based location sharing service and rather dismissed it as another PlayTxt or DodgeBall, both of which are now shuttered, and argued that EchoEcho fails my Theory of Stuff.

Nick Bicanic, the CEO of Purpose Wireless, the company behind echoecho was good enough to look me up and drop me a long email commenting on my blog post and -- very politely -- pointed out that I might want to revisit my opinion of the service. An edited version of that email to me formed the basis of his latest blog post on the topic of location as a context.