Post a jpg of your comp to the web and send them a URL?
Put it on your laptop or flash drive to present it on screen?
Print it out and show them a paper version?
Post it Online
There are a few downsides to this method though. For starters, you lose all control over how the client sees your hard work. No matter how many computers they have at their disposal, a client will inevitably choose the slowest one with the most obsolete browser and least flattering display.
Obviously, meeting in person isn't always practical, especially if the client is more than a short drive away. When the option is available though, take advantage of it.
When I have brought along a computer, I've noticed that clients tend to get distracted from the task of reviewing your comp.
By printing out a design, you have precise control over what the client will see, and reduce the possible distractions which technology can bring to the table.
