I'll have some brilliant wildlife/seascape photo opportunities when I go away on holidays next month and I'd be endlessly grateful if you kind folk took a minute to suggest some lens options for my Nikon D40. I mainly use my 18-200 these days and I really like it, but for wildlife/seascape are there other lenses you'd recommend? Autofocus would be nice, but I'm aware of the restrictions with the D40. Budget - in the region of e500 / $800. Thanks.