I am going to use Google as an example because this is what I’m most familiar with. keep in mind that there are alternatives out there.
When I finally voluntarily surrendered my company mobile phone (alas, goodbye Blackberry) I had to shop around for a cell phone. I wanted one that I could connect to my Windows PC without third-party software and keep it in sync. If I would have taken more time to research I probably would have settled for a different phone. For those who don’t know, syncing your phone to your Outlook does not configure your phone to receive emails direct from the email server. So the only time your phone will sync is when you connect it to the PC.
Enter Google, my hero with shiny teeth and spandex. Now without the need of special applications or complex configuration now I can sync my information from one central point. From the Gmail website with Google Sync, I can update my contact list, calendar, and not miss any of my emails on my Windows Pocket PC. Availability of each service vary depending on your platform [what you are computing on].
Maybe your current communications management provider (i.e.: Hotmail, Yahoo! Mail, AOL You Got Mail) has some form of syncing services. But compare them to what Google offers and seriously consider migrating!