Today's Portobello Road bargain...

...was an immaculate Helios 58mm F2.0 lens - for £3! It's Pentax screw fitting but they're very good lenses and still in great demand as portrait / macro lenses. The one snag is that it doesn't have a stop-down switch on the lens - presumably they thought everyone would use the camera button for that. Even so it's probably worth a lot more, so I bought it and put it out on eBay, along with my usual range of computer tat etc., we'll see what happens.

http://www.ebay.co.uk/sch/marcusrowland0/m.html