They generally tend to have the same features (note, I'm not doing a comparison here...that's been done / being done elsewhere) involving some kind of 'add-on' to the browswer to shift the page into your account seamlessly with browsing as well as some combination of tagging, organising, commenting on these bookmarks.
Onlywire provides an interesting approach...it aggregates your bookmarking efforts. Prompted by the list of 20 or so sites, I created accounts for all of them and will explore further, though my suspicion is that Del.icio.us will remain my favourite. I like Furl's greater sophistication in terms of managing and organising (better bibliographic features), and see Diigo as very useful for its annotations capability but... I wonder if I can break my loyalty.
Of course, there are 100s of such sites and services. In 2006, one blog had collated over 200 bookmarking sites (http://3spots.blogspot.com/2006/01/all-social-that-can-bookmark.html), as well as 300 news aggregator sites.
Three questions emerge for me:
- what is the impact on the whole understanding and value of tagging when, more and more, tagging and public bookmarking becomes a tool for self-promotion rather than a collective, uncontrolled 'swarm' research task? - This question is prompted by Onlywire which, explicitly, suggests you use its functionality to put tagged bookmarks on as many sites as possible from your own website, blog etc.
- what is the consequence of people becoming associated with 'sites' rather than technological possibilities? I mean by this question: while we might talk of 'tagging' in the general sense, if I always / mostly use one tagging/bookmarking site in particular, and have loyalty to it (because of my content, my familiarity with it, my pointers to it), then I am not in the same category as a person using another site, even though engaged in the same generic activity. Essentially, just as TV programs used to (still do) generate a loyal audience aggregated for advertisers to buy, so too do these sites. Yet, we are not fully conscious perhaps that 'tagging in Delicious' is not the same as 'tagging in Furl' because the very same action, for the same result, constitutes two distinct audiences determined by the lock-in to the site, rather than, as with other media, different audiences emerging around different programs.
- do we yet understand the process by which multiple instances of the same broad service come into being, with some prospering and others not, and how does this process affect the kinds of services that, after the 'shakeout' and 'buyup' leaves us with just a few, we end up using. Do we get the best? the easiest? the coolest? or what?