Penguin has the perfect solution for those busy people without the time to read a full length novel - bite-size tales! I remember the last initiative - little, orange-spined books that opened up new worlds, certainly for me. I still have a batch of them on my bookshelf, including works by Patricia Highsmith, Saki and Virginia Woolf.
Of course, if you like your fiction short but don't fancy anything that could be defined as 'literary', you could do worse than checking out Byker Books' Radgepacket series, Pulp Press's novellas, or Legend Press's short story collections. Enjoy!