Updated: This solution is pretty lame, and also fails the test case pointed out by Anonymous Monk. Use antirice's solution.

Well, I really doubt that this is the nicest way, but it does use split. (Mind you, it needs a regex substitution first...)

use strict;

my @strings = qw (ThisString SomeOtherString);

foreach (@strings) {
  s/([a-z])([A-Z])/"$1:$2"/eg;`
  my @tokens = split /:/;
  print join "\n", @tokens;
  print "\n";
}

__END__

# Output: 

This
String
Some 
Other 
String
[download]

</ajdelore>