Will that effect anything I have running the background (CA Security, MS Security Essentials, Skype, Internet)?
loose at least one of the security programs. Personally, I don't use any security, other than a weekly visit to Housecall (its a free online virus remover that installs its' self, removes viruses and threats, then uninstalls it's self when it's done so you don't loose cpu to it most of the time) then monthly or when I get a bad virus, I install someting real like Norton, or whatever long enough to remove whatever housecall is missing (usually nothing) then get rid of it.
If you have important things on your computer, you will want to keep one of your security programs, but there's no reason to keep both. Not only will they waste resources just having 2 of the same thing, they can find false positives against eachother and further drain your resources fighting. Dropping to 1 or 0 if it's a gaming computer will help alot.
The other thing you can do is to run it on a ram drive.Follow the directions here: http://www.bwana.tv/forums/index.php?threads/minecraft-running-slow-try-ramdisk.41183/ If you want to do that. a 768 mb ram drive with the 512 mb memory you allocated to java will leave your computer with 3/4 of a gig left in memory to house the os and background programs which should be enough and will make chunk loading nearly instantaneous so there will be no lag spikes. A ram drive will not help fps, but it will eliminate the chunk loading lag spikes.