What to use instead of memcache

[xester]

I'm using memcache for caching (obviously) which is great. But I'm also using it as a cross-request/process data store. For instance I have a web chat on one of my pages and I use memcache to store the list of online users in it. Works great but it bothers me that if I have to flush the whole memcache server (for whatever reason) I loose the online list. I also use it to keep record of views for some content (I then periodically update the actual rows in the DB), and if I clear the cache I loose all data about views (from the last write to db).So what I'm asking is this: what should I use instead of memcache for this kind of things? It needs to be fast and preferably store it's data in memory. I think some noSQL product would be a good fit here, but I've no idea which one. I'd like to use something that I could use for other use cases in the future, analytics come to mind (what are users searching the most for instance).I'm using PHP so it has to have good bindings for it.