Webapp Pingie takes any RSS feed and alerts you of new items in that feed via SMS message. It would be a bit ridiculous to subscribe to the full Lifehacker feed (or other frequently updating sites) with Pingie, because no one really wants 20-plus text messages a day. However, for lower volume sites, services like Pingie or previously mentioned Web-alerts could come in very handy. Pingie is free to use, requires an email address to set up your account.