Digital cameras have become so simple that many people end up taking more pictures than they have time to upload to their computers. Eye-Fi, a startup in Mountain View, CA, hopes to change that with its new two-gigabyte secure-digital memory card, which turns any compatible camera into a wireless transmitter. When a camera containing the card comes within range of a preselected Wi-Fi network, the card automatically uploads its contents to a local PC or to a designated photo-sharing site on the Internet.