After digging through some of Ryanair's news, I've just found that they'll be releasing some penny flights at 14:00 today. Apparently there'll be 1000 seats available for every 10m Euros that aer lingus loses, as announced in their annual reports today. Given that Reuters say that they've lost 107m Euros, there should be 100,000 seats up for grabs.
As ever, to find the free flights you need to check ryanair's homepage to see what routes are available from your chosen airport, click the route your interested in to find what dates the free flights are available between and then search for flights that say "NO TAXES" next to them.
To avoid extra charges make sure you elect to take only hand luggage, deselect priority boarding, deselect the travel insurance and pay either by a visa electron card, post office travel card or via Entropay.
For those of you who've seen the news stories this morning about Ryanair planning on starting to charge for web checkin, this will only apply to those using web checkin and dropping off bags at the airport initially (they're going to start allowing that, and to allow non EU citizens to use it) and when it does get rolled out to everyone it still wont apply to "promotional fares" (the ones we all like to use, likely to avoid the wrath of the ASA)