My new toy, an Asus eeePC. With this little beauty, I can carry around with me books and books worth of information, easily searched and cross referenced. There is no hard drive, just flash memory. 4GB internal memory, with an SD card expansion slot, which currently offers an extra 16GB of space. There are also 3 USB ports, which means I can further expand storage with a few USB storage disks. I currently have the database from Biblia Clerus installed, which is downloadable free from their site, and the content from New Advent, which is available on CD which can be ordered from the website for a small price.
The Asus is very small, much smaller than the average laptop, for those who recall them it is reminiscent of the Psion 7. The Asus runs on Linux, but I have Windows XP installed on mine, not because I'm a fan of Windows in any way, but this way I know the databases I want to store will work.
The Asus weighs less than a kilo, and I can easily access and reference the Catechism, the Holy Bible (Douay Rheims), the Summa Theologica, writings from the early Church Fathers, and documents from the Church councils.
I will always prefer reading from a book, but for convenient portable reference with access to all this information the Asus is ideal.