SSDs.

The not necessarily brand new, but a subject worth covering.
ssd have had long enough now to come in capacities of normal hard drives, but unfortunately the prices associated with these are more than extortionate.
For a 1 terabyte ssd, the prices are in the thousands of dollars.
When you can get a 1 terabyte hard drive for around fifty.
Again, although i'm English i'm talking in dollars because that's where my audience seems to be.
Although the kind of ssd you need will ultimately come down to how you intend to use it.
If you're going to be using a ssd as a primary and your only drive then you'll need a drive with an equally good write speed as read speed (OCZ have good drives for this, 285mb/s read 275mb/s write. Although if you're only using the ssd as the operating system drive and then a larger spinpoint hard drive as the slave then you can negate a larger write speed for a greater read speed (Corsair C300s are perfect with 355mb/s read 75mb/s write).
PCI-E ssds are even faster, but the speed does come with a considerably larger price tag.
A 50gb PCI-E ssd will cost you $215, that is a serious amount of money for such a small amount of storage.
Even with 540mb/s read and 450mb/s write.

In summary, if you're willing to purchase a ssd for the prices which are around then go ahead.
My recommendation is get an operating system drive, like the Corsair C300, then just have a larger spinpoint drive, for instance the Samsung F3. This combination would cost $185 from newegg, that is good for the speed and capacity you would be getting out of it.

I'll see you all again, but goodbye for now.