I used to love Microsoft Outlook. It has a pretty interface, especially compared with Lotus Notes, which was the application installed at work years and years ago. Compared to Lotus Notes, counterintuitive and clunky, Outlook seemed wonderfully quick and light on its feet.
Until fairly recently, when I began to notice Outlook activity slowing my computer to a crawl.
But in general, I remained comfortable with Outlook, which retrieved my mail from my Internet provider's server on a scheduled basis--every half hour, or every minute; however I requested. The obvious advantage of more frequent retrieval: getting my mail faster. The disadvantage: my laptop tended to pause for the occasion.
Then I got an iPhone. And wondered how I could get my Outlook mail synchronized with it. Certainly the mail came into my Inbox just fine, but the folders didn't match. A little research, and I discovered IMAP. And Gmail.
I had known of Gmail for a long time and found it resistible. The interface didn't attract me. Busy, dense with text...frankly ugly. However, since my alternative was sticking with email that didn't match my iPhone, or paying Microsoft $99 a year for a new email address (MobileMe), I decided to give Gmail a try.
I now use not only Gmail, but Google Calendar and Google Tasks, as well as Google Contacts. The advantage? All this information is simultaneously available not only via my iPhone, but via any computer, using my Google account. Further, I haven't opened Outlook in months and don't miss it. I've started using GoogleDocs more, too.
Now the application that slows my laptop most is iTunes.