You should try doing a path>Simplify... command to reduce the # of anchor points, although depending on the level of detail you need to maintain, this can be a tricky process.

good luck.

You may also want to use the 'flatten artwork' command in the layers palette if you still have it on mulitple layers and then use 'delete unused palette items' action in default actions to help reduce the file size some more. You may also tweek your PDF settings to help reduce the file size that you are saving it to as a PDF.

Check on embedded or linked images in you file. A billion anchor points and a file over 50 mb makes me think that you use live trace (or streamline) to trace over a raster image to convert it to vector. If that is the case, then you might want to check your links palette to make sure that the original raster image isn't embedded in your file. If you have a raster file linked to your illustrator file, then when you are saving it to PDF the increased file size could come from the program embedding the image in the PDF copy.