I liked the idea of Tim Bray's letter sweep http://www.tbray.org/ongoing/When/201x/2011/03/03/ABC so I've done the same thing.
[a]mazon.co.uk - birthday presents, the odd CD for me.
[b]logger.com - editing this blog.
[c]olly.com - web designers blog. If I click through his feed from Google Reader it never works, so I go straight to his site. Perhaps I ought to tell him.
[d]ownforeveryoneorjustme.com - Useful if a site goes down.
[e]urotp.org - the website of our training organisation. At the moment I'm in between reworks.
[f]acebook.com - like [insert latest stat here]% of the population.
[g]uardian.co.uk - I heart The Guardian.
[h]something - our local intranet.
[i]something - our organisation wide intranet.
[j]obs.wycliffe.org - runs a couple of apps listing vacancies and asking lots of questions of potential recruits.
[k]ingsgateuk.com - I was finding out this churches postcode.
[l]not disclosed for security reasons
[m]anypies.paulmorriss.com - this blog.
[n]ews.bbc.co.uk/weather/ - always good to know.
[o]utlook-trust.org - they use some of our spare office space. We have more available!
[p]aulmorriss.com - my site.
[q] - no default, but the most useful on in the suggested list was this interesting article quora.com/Microsoft/Why-doesnt-Microsoft-understand-tablets.
[r]eplay.waybackmachine.org - previous versions of websites.
[s]tackoverflow.com - top quality programming answers.
[t]echmeme.com - tech news aggregator.
[u]nionbaptist.org - my church.
[v]alidator.w3.org - essential web developers tool.
[w]ycliffe.org.uk - our website, I'm always working on minor changes.
[x] - no default, the most useful was this site about wikis built on the engine that stackoverflow.com uses (don't know why it came up under x).
[y] - no default, though I do visit youtube.com .
[z] - no default, though my recent search for "zero inbox" was at the top.