*Lurker peeping out for a change*
I'm not sure asking is the best strategy. I've gone to my boss (no formal review process) with concrete numbers justifying a bump in salary. In my case, I was managing a large-ish restaurant and I was directly responsible for lowering labor costs, liquor costs, comps in general, and had been mentioned by name in a couple of positive reviews. Also, I'd taken on responsibility for creating nightly specials menus (the chef was willing to not offer specials at all, which jacked up his food costs--he blamed that on servers' mistakes, which was BS) with some items that sold (no pun intended) like hotcakes.
I asked my boss for 15 minutes, laid out my pitch ("Over the past eight months, I've...") and then told him that I felt I'd earned a piece of the improvements that I'd brought to his business. He grumbled, but eventually I got my raise...and a bonus based on P&L. Now, I knew this guy--had I asked for a raise, he would've laughed me out of the meeting.
I guess what I'm saying is don't be afraid to testify about your own worth as an employee, rather than asking someone to recognize it. You might not get a raise, which is where the market rate info/other job offer could save the day. Yes, it's a slightly more ballsy approach, which isn't always a good thing. However, being direct in this matter could lead the way to additional responsibilities later. Right after my meeting with the owner, he had to mediate a showdown between the chef (highest-paid employee there) and me over the chef's treatment of one of my servers. I won that showdown, and I'm not sure I would've had I not gone to him and made my case for a raise.
Just food for thought...