iPhoto's export capabilities are fairly limited, but they should suffice for most situations.
To export files:
Select one or more photos.
Choose Export from the File menu ().
iPhoto displays the Export Photos dialog (Figure 8.12).
Figure 8.12. Use the File Export pane in the Export Photos dialog to choose the format, scale, and name for your exported images.
If it's not already selected, click the File Export tab.
Choose the format for the exported photos from the Format pop-up menu, select an image scale, and select how you want them named. Then click the Export button.
iPhoto displays a Save dialog. Navigate to your desired folder and click OK to save your images.
iPhoto can export into only JPEG, TIFF, and PNG formats. For other formats, use a tool like GraphicConverter; see the sidebar to the right.
Only JPEG files can be scaled to a different size; if you save in TIFF or PNG format, you're stuck with the full image size.
When iPhoto scales an image, it does so proportionally with the limits you set.
The point of the Original item in the Format pop-up menu is to enable you to export a RAW file, GIF file, or other file format that iPhoto would have converted to JPEG when it was edited.
If you export only a single image, iPhoto gives you a chance to rename the image manually before saving (Figure 8.13).
Figure 8.13. If you export only a single image, iPhoto lets you name it from within a dialog.
If you want to do anything more than basic exporting of files, try the $30 shareware GraphicConverter, available at www.lemkesoft.com/en/graphcon.htm. GraphicConverter is far better at converting images between formats, resizing them, and performing many other useful tasks, a number of which can be done in batch mode on an entire collection of images.