It occured to me that polling Recent Changes, based on the time since
last polling is maybe another solution to this.
What I like about this is that, if it was implemented:
- It would automatically work for *any* MediaWiki installation
- It would not be hard to add support for other wiki implementations
- It's entirely external to MediaWiki (no code changes) and should be
fairly low-impact (poll once per hour?)
You are then free to offer a variety of services to an unlimited number of users
- email on each edit
- email no more than once per hour/day/week/month
- email after 5 (or more) edits
- sms / text to mobile/cell phone [1]
- IM / irc of any variety
- update rss feed
[1] In the UK you can do reverse billing, which means WP could earn
money when WP sends an SMS to someone, assuming the someone has signed
up for this service. I suggest this would be a way to raise revenues
for WP and could be run as an entirely independent project.