This old chestnut really is an old trick (which may become new one day) about begging for money on your site. In most cases this makes you look desperate, but it might work nicely if you are a charity.
An interesting article was posted about how to put a Paypal “donation” button on your blog.
I had one on my Canadian Financial Place site for a while and never got any money from it or even any clicks, however, I did end up with someone contacting me directly by reverse engineering things and seeing where my Paypal account pointed.
I was lucky that this person was simply querying me about advertising on the site, but I was taken aback by the fact that I had not remembered that my Paypal account and my “public” e-mail account are not the same. I have since removed the donations button, since it really didn’t do me that much good, and it seemed to be a “security hole” in some ways.
If you want to put such a Paypal Button on your Blog click on the article here.