Its not worthless, but you won't get much for it. its a good camera - it may be only 2.6? megapixels, but it gives good honest pictures, and it has a good zoom.
You could try asking on dpreview.com. there is a sony forum on there and there might be someone lookign for one, either for themselves or as a present - many on there will have used a 505v in the past so may have fond memories.
What are you looking at replacing it with?