On the 3.0 iPhone software you can now email more than 1 photo at a time. To do this, from the camera roll tap the icon in the lower left corner of the screen. You can then tap on photos to select them. Once you have the ones you want, tap the Share button and it'll allow you to include them in an email.

The one big problem with this is that they still limit the number of photos. Instead of 1, the limit is now 5. But thanks to copy-and-paste, you can get around this limit of 5 too. When you are selecting photos, instead of tapping the Share button, tap the Copy button instead.

You can then switch over to email and paste all of the selected photos into the body of your email (hold your finger down for a second, lift it up, and then select the Paste button).

Using this trick, you can email as many photos as you want at once from your iPhone.