At the very least I would register for it, and tick the 'I can't attend', last year they put up the recording + presentation of the lecture and all the materials they hand out on their website, so there isn't a 'need' to attend. You might want to email them just to double check if they'll be putting the recording up online again this year (I would assume they would be).
I watched the IT Apps lecture online last year, it was quite good and got quite a bit out of it even though I didn't attend the actual lecture.
Seeing that you can watch it online, it's probably not worth the time you're going to waste travelling, particularly since it's a weekday and about a week away from when exams begin - it's probably better to spend that time studying for exams rather than waste 6 hours of your day travelling.