You can get through a few emails on your phone, maybe. Possibly look up a few things on the iPad. If you're in first class, maybe you could even get the laptop out and work on those spreadsheets.
Or, you could really go all out and do this:
A lady has brought her iMac onto the train! Has she **t heard of a laptop?? wtf!!! pic.twitter.com/zC3wNw7Yhv