SnugUp. It actually synchronizes a folder on my local PC with SmugMug and keeps it in sync when I run it. I have mine set to automatically hide/secure the new stuff it puts up until I release it.
Remember that most residential internet has very limited upload speed. Not sure what you have but this is probably your limiting factor.
I use Lightroom for all of my photo organization and post-processing. It has the ability to automatically upload photos to Smugmug and keep your folders in sync.