So what are we using?

Air Sharing for iPhone

Can’t go past this for a wireless file sharing app for the iPhone. Viewable formats include: iWork, Office, Web Archive, Web Page, PDF, HTML, RTF, RTFD, Plain Text, Source Code, MPEG-4, H.264, 3GPP, all iPhone Audio formats, and Image formats including Gif, PNG, JPG, TIFF, and more. The file browser also features pinch zooming and landscape mode.
Visit iTunes for more info

IDrive

Like most, I have a few portable backup drives however I do not like carrying them with me all the time. So to keep it simple I now use IDrive on a daily and weekly basis. With scheduled backups and 2GB of free storage, you can’t go past it for a free online and backup storage service.
Visit the iDrive website

Synkron

Until recently I have been a big fan of SyncToy, now I am using Synkron on the Mac and PC. A nicer, easier to use interface and of couse, there is a Mac and PC version unlike some other Syncing apps. If you’re into it, there’s also a portable version!
Visit website

Of course, none if this would work without an Internet connection and if you’re going to use Air Sharing it will have to be a wireless one.

For an alternative to IDrive (for stoage only) you could use Box.net.

Hardware is a DELL Latitude with XP, MacBook Pro with OS X and iPhone 3G. Internet connection and iPhone data both with OPTUS.