On the complete other side of things, I'm the person who has to spend $2,000 to ge to people's weddings because I live so far away. By the time I've bought my flight and accomodation I am not in the mood to throw more money at the people in questions wedding - I've only had one person out of 8 ask me when they could expect my gift, and I told them in no uncertain terms that their gift was the money and effort I put into getting to their wedding. Not to mention I'd planned it for her for free. Grrr. It bothers me after all that that I'm the one who ends up looking cheap.

As for the thank-yous... I think a thank-you should be sent to everyone who showed up to support you on your day, regardless of whether or not thay gave you a gift. Word them along the lines of

'It meant so much to us to have you with us on our weddign day. The support, well-wishes and gifts we recieved from our guests were overwhelming, and we are thrilled to have such a wonderful group of family and friends with which to share our lives'

People have all sorts of reasons for buying or not buying a gift - but in the end the thanks should be for them sharing your day - not material goods. Send the note without specifying a gift if you're not sure if they gave you anything or not. They still made the effort to be there for you, after all. I haven't recieved a single thank-you from any of my British friends who I flew home to be with for their weddings, (nor are any of those friends returning my gesture and flying out to support me - but that's another rant altogether) yet if the measure of a thank-you is based in pounds and pence, I spent significantly more than the average guest in order to be there.