With wedding speeches there's a huge temptation once you've been given those 5 minutes in the spotlight to chuck everything at it. There's a misguided belief that by turning yourself into a 20 minute one man entertainment whirlwind, something you'll have covered, performed, sung or indeed acted out will have tickled every guest there in some way. In my opinion ramping your speech up to be something you could take to the Edinburgh Fringe is a one way ticket to failure.
The absolute golden rule is that you must never tax the people who are sitting there listening to you. If they're relaxed and comfortable they're going to enjoy the speech. If you start making demands on them they're going to lose patience, and pretty quickly too. If I'm listening to a wedding speech I want to be able to sit back, drink wine and listen. I don't want to have to find a sheet of photographs and then work out why they're funny. I don't want to have to listen to some song being butchered in the name of comedy and above all I don't need a powerpoint. Anything that takes the attention away from the person is actually speaking is wholly counterproductive and you should avoid at all costs, because getting their attention back again can prove impossible.
By engineering things in like audio visual props you really are just making life more difficult for yourself. At the time you may think it's a neat way of using up minutes without having to say very much but nothing is easier to deliver and gives more genuine funny pleasure than some well crafted words.You don't have to find a power supply, you don't have to locate or bring in a screen and you're not at the mercy of technical glitches. All the guests have to do is sit there and enjoy. If you think that delivering your speech in an effective way involves powerpoint then stop. What works for a room full of men with security laminates is very different to a roomful of guests in wedding mode. Powerpoint will only ever be associated with being lectured and if you want to engender that kind of vibe in your wedding speech, then go right ahead.
Keeping things simple also means keeping them to the right length. There's nothing worse than a long wedding speech and if you haven't said all you need to say at around the 7 minute mark, you really need to do some editing. Talking ad nauseam hoping that you stand more chance of saying something funny is a tactic doomed to failure, and if you're actually deluded enough to think that you've managed to write a funny 20 minute speech then seek help. You should only ever be looking at a speech around 1000 to 1200 words and your cut off time with heckles, applause etc should never be more than 10 minutes.
There's no replacement for a well written, funny heart warming speech. It should give a great deal and ask little in return, and also be a lot easier to put together than an audio visual extravaganza.