tif to jpeg on a Mac

[Kipper]

I have scanned a number of photos into iphoto on my Mac. I want to put one of these onto another forum, but they do not recognise tif images. Is there any way that I can change the format of the images?

[Pengi]

Open the image in Preview, then select Export (from the File menu) and the 'Save' screens come up. Choose jpeg from the format drop down box

[Kipper]

Thanks Pengi! All the gear and no idea, and a Notts Luddite to boot.