I was a late adopter of Twitter, joining just a little under a year ago, and tweeting mostly about making tea. I’ve written about Twitter here rather a lot in the year since, either referencing it directly when discussing OhMyScience or my favourite STEM engagement project of 2008, the Mars Phoenix Lander twitter stream, or simply reposting things I learned from people I follow.

One convention on the service is to tag tweets about specific events or subjects with ‘hashtags‘, short unique strings prefixed by #. For example, for the BIG Event this year we’ll likely use #BIG09. They’re only a convention (at least for the moment), but they do at least allow people to define ad-hoc groups around events or shared experiences.

Looking for that group, however, is not straightforward – the tools are lagging the convention somewhat. However, as an aide-memoir (and a post for posterity, for some indeterminate time in the future when this all seems so primitive. Perhaps three months from now), here are some services that help:

  • Search.twitter.com does a decent job of finding hashtags, and updates the page to alert you to new hashtagged posts.
  • Hashtags.org attempts to catalogue hashtags, but seems more about trending topics than ‘finding everything under a given tag.’ Twitter search also collates trending topics, but from a straight keyword frequency plot, rather than by hashtags.
  • Twitter Groups looks interesting – using hashtags to define groups by interest rather than event. Anyone using it?
  • Twemes is another attempt to pick out what’s hot and trending in the Twittersphere.
  • Twitterfall is something that’s been asked for regularly – a constantly-running search that updates as a column flowing down your screen, so you don’t have to refresh.

Ultimately, I worry that the ‘trending topics’ type analyses can’t conceivably scale, as Twitter grows. I can sort-of believe Twitter Search being able to sample a representative proportion of tweets, but surely anything else is going to be flaky, with access to only a tiny fraction of ‘the firehose’? In which case, they’re simply showing what lots of people are talking about. The whole point, surely, is to spot fast-growing minority topics?

Twitterfall is nicely done, but I fear it’s not necessarily that useful in practice. If I’m following, say, #omc09 (the Oxford Media Convention), I’m more likely to want to see everything tweeted there, not miss stuff if I blink. But there may be situations when I want auto-refresh, I suppose. Nice to know it’s there.

Finally, there are activity aggregators, Friendfeed being the principle player here. Many people swear by it, but I’ve never quite got my head around it.

An interesting development is the next version of blogging/CMS software Movable Type Pro – Motion is a roll-your-own activity aggregator, based off the system driving the Action Stream page here. I’ve yet to play with it, but look forward to doing so – I should also play around with Action Streams stuff, and integrate it with the main flow of the blog somehow.

There’s something rather appealing about being able to pull content from around the web – people talking about your product or project, for example – and catalogue it in real time, on your own branded page. It’s a dangerous concept, but a powerful one.