No great story about the history of my name, but I went through a couple aliases before arriving at the all-to-common one of sirlancelot...
When I was really young (we’re talking like, 8-12 years old), I picked the alias Ice. I kept it for a while until I grew older and found out that Ice refers to a certain drug and didn’t want to be related to that in any way! I later adopted the name Fusion because of the variety of groups of people I could fit into, the geek crowd, the "cool" crowd; I called myself a fusion of personalities
I went through some various spellings and styles of the alias (NeoFusion, Fiuze, SilentFiuze) before I got tired of it and decided to move on because I had used so many variations on the alias I forgot what I had used for each website!
I finally arrived at the alias ’sirlancelot’ for a couple reasons: while it is still fairly common around the net, I still got pretty lucky with its availability on most of the sites I visited. GMail was the first place I used it; back when It was invite-only beta status (meaning very few users). The second reason is because it’s just fun to type out on the keyboard! Finally, it’s really simple to spell out in writing or speaking, there’s very little (or almost no) variation in how it can be spelled so when I say "sirlancelot" to someone they know how it is spelled. This is not true of the alias ’Fusion’ as I showed above.
I will always type it in lowercase letters because I’m a linux user and am deathly afraid of capital letters on my filesystem