Like many others, I kept a journal well into my teenage years, finally giving it up as the time constraints of adult life intervened. Reading through these memories is still a source of amusement and pleasure. I think that is why I find the concept of Memiary so compelling; it is a focused, minimal and (most importantly) available diary-keeping tool for the electronic age. The principle is simple enough--record up to five daily events that you would like to remember.
The Memiary service has existed on the web for some time and the iPhone app is a companion that synchronizes with your account. The app allows you to record your memories within the program and sync/backup online. It offers a very basic daily template, namely a list of 5 items for you to record. There are other niceties incorporated within Memiary that make it more user friendly. It supports the use of hash tags for categorizing and searching items within your posts. The online navigation bar allows you to browse by date, time or tags; you can read or edit posts from the past week, month, year or all-time (this function is also supported within the iPhone app).
You can also set email or Twitter reminders for yourself, as it is naturally easy to forget to fill in the blanks on a busy day. Memiary offers full integration with Twitter. Although it is a bit cumbersome to set up, you are able to record events to your Memiary account via Twitter; however, I'm not exactly sure this is a selling point for the companion iPhone app! Additionally, any of your recorded events can be exported to iCal, Outlook or Google calendar, again only from your online account.
The iPhone app has some annoying bugs that need to be addressed. The synchronization is "funky", often omitting random events and putting days out of order on the week and month views. In addition, the pop-up keyboard hides items #4 and 5; there is no screen scrolling, so you are basically typing blind.
I am enamored of the Memiary concept and find that its iPhone companion app to be useful as I am often away from a computer for days at a time. An update to fix the bugs and add some of the functionality available online would make it indispensable.