Linux guidelines or no, it's 3 space indent for me. Why? Well you are always going to run into someone who has their tapstop set different than you, or someone is going to mix tabs and spaces, so converting all tabs to spaces ensures your code renders nice and cleanly.

3 space is just the right about of readable to me, I really can't explain it. I guess I don't like to see a lot of whitesapce, and 2 is not enough for me to read indent levels quickly.

Also, when I feel like it, I intent places that typically are not intended, such as parameter lists like in Tk or OO functions:

Whatever::Foo->new( 
   -bar => 'xyz',
   -baz => 'def',
);
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Let's not start the flamewar as to where curly braces go, but I like them on the same line as the if, since (at least to me) scrolling cuts into readability. At least Perl enforces blocks on if statements!