Although an iPod will save you money, it will also create work for you or one of your guests on your function day. It can also create tension among your guests if more than one person wants to control it.
An iPod sadly cannot read your crowd and therefore cannot change the mood at any given moment.
iPods will often play the wrong song at the wrong time and at the wrong volume.
Save yourself the stress of putting the music together and worrying about how it will run on the day and hire a true professional DJ, live musician or band for your corporate event, ceremony or reception. The sound quality will likely be far better than many of the small PA systems your venue may provide or hire to you and it is almost certain to be more engaging for your guests, creating a much more fun and memorable event.
Professional entertainers can also troubleshoot technical issues seamlessly and adjust volume levels between speeches, music, and microphones (for ceremony, toasts, etc.) easily.
They can also give you tips on the ideal set up, and the best music to play to build the momentum for the various phases of the night.
Through our own experience and liaising with many venue coordinators who have seen iPods fail at an event, we would recommend that you strongly consider budgeting for entertainment at your function and saving your money on something else that will have less impact on the success of your event as a whole.
Bottom line: Leave nothing to chance. If you want a memorable wedding or event with the greatest potential for fun- hire a professional DJ or live entertainer/band.