Converting internal to external optical drive?

I am pondering going for a netbook, but the ones I am looking at lack an optical drive. I will hardly ever need to use one so this is not a deal breaker, but if I end up having to install some software (or OS even), I would need one. I have a ton of old laptop slim drives and even full size desktop burners. Is it possible to use one of them without an enclosure? I would rather just use a cable and slim drive as this would spend most if not all of its days in storage so smaller is better, but I do not know if this is possible. If not, are there enclosures for slim drives as I have not found anything.

Thanks!