More convenient ways to communicate than a floo network.
Something like a combination of two-way mirrors and floo network. You say an address, the other person accepts your invitation and you chat. Much better than being on your knees next to a fireplace, while your head is on fire in a different location (can you imagine how uncomfortable that must be?). Or instead of mirrors, perhaps something like crystal balls with same purpose?

I did always wonder how would wizards react to the internet. There is a lot of technology that is considered unnecessary and weird by wizards, but who knows if wizards would consider making their own version of the internet. If such a thing was approved (after much debate), then I can imagine magical governments strictly regulating it in order to preserve the statue of secrecy, perhaps only limiting it to approved shopping websites, business sites, tourist sites, official magical government sites etc. The magical device that is able to connect to this "wizardnet" would be strictly restricted to magical homes and schools (like Hogwarts). Such devices would be extremely useful and something that wizards didn't have before.
I refuse to consider the possibility of forums and social networks, because that would ruin the magic of HP world. Let's just say that the wizards laughed that idea off.