Enumerate all palindromic numbers (in decimal) between 0 and n
Perl 5.10, 29 (or 39) characters

say for grep$_==reverse,0..&lt;&gt;


Needs the say feature enabled. 29 chars if you consider that to be free,  otherwise 39 to add use 5.010;. Argument on STDIN.

Perl, 35 characters

#!perl -l
print for grep $_==reverse,0..&lt;&gt;


using the old perlgolf convention that #!perl is not counted but any flags following it are.

Perl, 36 characters

print$_,$/for grep $_==reverse,0..&lt;&gt;


If none of the others qualify.