The main situation where I find the Touch especially useful is for traveling. There's the music, of course, and the games, but the key thing is that I can go away for the weekend without feeling the need to bring a laptop. With the Touch, as long as my hotel (or the hotel I'm standing outside of) has WiFi, I can check my email, search for restaurants (UrbanSpoon app), make and manage reservations (OpenTable), and find directions. At the same time, it's awkward enough that it's hard to just sit and surf on it all day, the way I might be tempted to with a laptop.
The Touch was the only form of computer we took when we went to Chicago for Valentines' Day, and it was great. We were able to find the information we needed, when we needed it, and focus on enjoying our trip together without being distracted by the real world - which to me sounds like the perfect honeymoon gadget.