I use a mid-2009 unibody MacBook Pro 13-inch, which has a 2.5Ghz Core 2 Duo, 250GB hard drive, 4GB of RAM, an LED-backlit keyboard and display, with around 5 hours of battery life doing actual work. I use this machine to write for MakeUseOf and Tux Geek, for school assignments, for listening to music and watching movies.