Smartphones are a good way to carry parts of your GTD system around with you. They can act as your calendar, task list, address book and notepad.
Smartphones all have some way of synchronising with desktop software such as Palm Desktop or Outlook. Apple's iSync, a part of Mac OS X, supports synchronisation between iCal/Address Book and several Smartphone devices.
The method of input varies, some use touch screens, script recognition, alphanumeric keyboards, numeric keypads or a combination.
Symbian is the underlying operating system on a variety of mobile phone handsets and devices. They include Series 60 devices, which are designed by used one-handed and therefore very easily pocketed and used, and Series 80 devices, such as the Nokia Communicator 9300 and 9500. Series 80 devices feature a full QWERTY keyboard and a laptop-like form factor which allows them to be used folded up as a traditional mobile phone, and opened up as a PDA/communicator.
It should be noted that presently iSync does not allow for the synchronization of Notes or Memos on the device. They are not synced and will live and die on your handset.
- RIM BlackBerry organizer/smartphone Syncs with outlook on Windows platforms or with Mac using PocketMac software (be sure to update to OS 4.0 as this has support for categories)
- Traditional QWERTY BlackBerry devices, such as the 7290 feature instant always-on email and a very servicable PIM. If you want maximum battery life, the 7290 or the other GSM models are the ones to look at, the CDMA and iDEN (Nextel) models are not as forgiving about being left off a charger.
- Other models, code-named "Charm" such as the 7100t, 7100g, 7100x, have a more phone-like form factor and a predictive text input method similar to Tegic T9 but better. It is called "Sure Type" and is actually quite nice after a day of use.
Using PocketMac with a BlackBerry allows you to syncronize Contacts, Appointments, and Tasks to iCal and AddressBook, or everything to Entourage. This includes notes, which is worth considering, since a lot of people prefer using memos and notes to track important information and want that to end up back on their desktop workstation or laptop.