We stopped immediately (one block away!) for the tour and lunch at the Dinosaur Cafe and Museum. The tour guide was reasonably well informed and quite willing to talk. He talked long after I wanted to stop staring at the dinosaurs and go eat, thanks. I'm sure that the Vilelings had a good time there, and that almost anyone could have a good time if s/he wanted dinosaurs with lunch. Lunch was good too. I ordered the roast chicken, and finally got hit with what CK's co-worker J. had led me to believe was the usual presentation - a plate with both french fries and baked potatoes. mmmm starch!
The drive back to Dublin was along the northern route through Limerick and across the N-something. We took the M-50 beltway around Dublin toward the airport, and got hit with a road toll that was 3 euros per person rather than per car. As FE put it, "way to encourage carpooling there!"
FE wanted to see Howth, so that's how we ended our trip. We stopped at the hotel to make sure that the room was ok (it reeked of smoke; CK supported me in getting it changed) then drove on out to the penninsula for an evening of walking along the coastline in the sharp breeze. I was coming down with a cold by that time, so we didn't go very far or walk for very long, but FE was gracious and declared herself satisfied nonetheless.
Travelodge Dublin Airport Ballymun gets only two comments of recommendation. The not-free wifi was of reasonable speed, and the shower had reasonable showerhead height. Other than that, it has nothing to recommend it besides proximity to the airport. The beds were hard as rocks, the lighting was either surgically bright or off, the bathroom was cramped, there were not enough towels until asked or room keys even requested, the one person at the desk (regardless of specific person) was neither friendly nor volunteering, and parking was a real PITA. So don't stay there.