This is a semi-rant because I can't believe Samsung missed this in product development. But, using the stock email app you can only attach picture files to outgoing emails. I have emailed samsung directly asking about this.
"Thank you for your inquiry. With the SCH-I500 mobile phone, you can only attach picture file types. If you would like to attach other files such as PDF files, you need to download an application through the android market for PDF application."
To me that sounds like they are telling me I need to go download another mail application if I want to attach other file types, which is ridiculous. K9 is an okay email app. The only other email app that does all versions of exchange well is Touchdown and it costs money + it isn't very asthetically pleasing. It shouldn't be that difficult for samsung to allow the stock mail app to attach any file type.
This problem also exists in the "Gmail" app, but if you download a file explorer application from the Android marketplace, the Gmail app will allow you to use that file explorer and browse for any file type.
Also, you can't open certain file types directly within the stock mail app. You have to save the file to the SD card first, then navigate to the file location and open it from there. This is a small pain, but still, it is not difficult to have attachments open directly from the mail application. My two co-workers Incredible's do this flawlessly.
I would NOT buy this phone if you are reading this post and you need to use this phone for business.