Having a dictionary about your person is always useful, but it's not always practical to carry a hefty tome around with you all day. Instead, you could simply install a dictionary application onto your mobile phone and never get stuck for words again. Whether you're using it to help you compose emails at work, taking it into an exam, or simply topping up your vocabulary on the bus, mobile-based dictionaries are a quicker and easier way. There are loads of different applications out there for every kind of device. Here's some recommended reading:

• Oxford English Minidictionary (UIQ) -  Ideal quick reference of core vocabulary
• Pocket Oxford English Dictionary (Blackberry) - RIM edition of the word guide
• SlovoEd (Blackberry) - Dictionary in five different European languages
• Concise Oxford Thesaurus (Windows Mobile) - Pinpoint the exact word you need
• Cambridge Advanced Learner's Dictionary (S60) - More than 170,000 words!