I used SimpleHTTPServer for a while, but I found it a bit sluggish at times. I replaced SimpleHTTPServer with http-server, and I've been very pleased with its performance:
If you have twisted installed (which is the case on stock OSX), you can use the twisted webserver, which is a lot faster than SimpleHTTPServer and supports concurrent multiple downloads & resumes. I use this alias:
https://github.com/nodeapps/http-server
Not standard (or Python), but it's a quick install, and I find it just as usable and much faster.