Usually when formatting obfuscations artists use the typical $_='...';s/\s+//g;eval; wrapper trick, which allows the source to be moved around to whatever position you want so long as the final lines that make the string runnable are runnable. For examples of this you can check out many of Erudil's obfu's, including Camel Code.

You have to be careful that your code is not dependant on spaces to run, and if it is find a way to either take them out or work around them. You can also help yourself during this process by putting in a die $@ if $@ line at the end so that if your code doesn't compile correctly after wrapping it you can find out why...

Hope This Helps,
jynx