[OS X TeX] Lambda Bar Symbol

[Richard J Benish]

Would someone please explain the most painless way to get a 
Lambda-bar symbol (as for Compton wavelength, a lowercase lambda with 
a bar through the ascender)?

I've downloaded Scott Pakin's list of symbols and find three or four 
Lambda-bars with their commands. None of them work on my system 
(TexShop 2.10, OS 10.4.11).

I went to the website referred to by Pakin for more info, but I 
didn't see anything of help (or I didn't understand what I was 
looking at).

I've never loaded a new font for LaTex before. Every time I've 
thought about doing so, the appearance of complicated rigamarole has 
scared me away. But now I need a Lambda-bar. Please help.

Thanks a lot.

Richard Benish