The wedding couple asks for RSVPs well in advance in order to gauge how much food they need, how large a hall they need to rent, and indirectly, how to arrange (reserved) seating. So going solo may ultimately wind you sitting in the "singles" table. Not a bad thing, but not good if there are desparate females seated with you. Weddings tend to enhance emotions of lovelorn women.
Gift registries are "suggestions" as far as I'm concerned. They were designed for the convenience of the couple, to eliminate duplicates, oddball chioces, or less-than-quality versions of a desired gift. Personally, I reserve selecting registry gifts for those couples I'm very close to, such as close relatives or best friends. You have no obligation as a co-worker to bring a lavish gift, but you do have an obligation to show up with one. Look at the registry anyway, as there may be a gift on the list that will match your budget...do so early, as the rest of the cheapo invitees will grab those options first.
Bring money...you will need it for the reception "cash bar" as well as folding money for the bride when you get your chance at a dance.
My worst wedding invitation? My absolute all-time head-over-heels crush-of-my-life, turned me down graciously when I got the nerve to ask her out back in high school, as she was already dating the captain of the football team. She married that same guy a few years later and asked if I would play for her wedding...yeah, right!
