I have built a small web application in PHP where users must first log in. Once they have logged in, I intend on showing a small thumbnail as part of their \"profile\".
I think that most database engines are so advanced already that storing BLOB's of data does not produce any disadvantages (bloated db etc). One advantage is that you don't have any broken links when the image is in the database already. That being said, I have myself always done so that I store the file on disk and give the URI to the database. It depends on the usage. It may be easier to handle img-in-db if the page is very dynamic and changes often - no namespace -problems. I have to say that it ends down to what you prefer.