Do I need a particular application to compress PDF files without losing quality?

I'm running OS X 10.7.4 on a 13" MBP that I purchased earlier this year. I recently also picked up an HP N6310 Scanner so that I could scan documents through the automatic document feeder in higher resolution than my all-in-one printer allows (i.e. 600dpi v. 300dpi).

To note, I only scan documents for the purpose of either archiving them or emailing them to clients.

The problem, however, is that, when I save a document, the resulting pdf file is huge (eg. about 2.5 mb for a one page document). I have tried compressing the file with the app built into my MBP, but it only trims about 10% off of the size of the file.

Is there an application I can buy that will allow me to compress pdf files WITHOUT losing any quality? It's important that the quality of the pdf file is not compromised.

Thanks.

Thanks for the reply.

Since I first posted, I tried using the Reduce File Size in the Quartz filter from the drop down print dialog menu, but the resulting image quality is pretty poor. It's important that I maintain true quality copies of the pdfs that I scan.

Is Adobe Acrobat the only way to go? I know it's an expensive app, but if it's the only one that will significantly reduce the size of my pdf files without losing quality, I will buy it.

Quite a Box of Tricks looks good, but two questions:

1) Does it maintain the quality of the pdf (i.e. no degradation)?
2) Can it be used without Adobe? If not, will it work with the free Adobe reader that is available for download? Never mind, I see on the website that Adobe is required. So, what's the advantage of compressing using Quite a Box of Tricks over compressing using Adobe?

Thanks.