It is very easy to set up a remote like a smartphone or tablet app. There are many of these. I have e.g. an iOS app for it. These apps do basically all the same: You can use it
1: like a remote with up/down/left/right/enter/play/pause... buttons, or
2: you can browse through your shows directly on your device.
If your TV supports the CEC protocol (remote-protocol via HDMI) you can also use your TV remote as the XBMC remote.
Solution 3 to ∞
I haven’t done this yet, but you can setup a lot of different controllers for your Raspberry Pi. To do that, you usually have to go through the commandline. And you probably want to choose the OS RaspBMC since it has a full Linux running in background. So with RaspBMC you have more possibilities of customization than in a smaller OS like OpenElec.