Guys, take out the list of rules you currently live by. Under “No fat chicks,” scribble in under that: “Also, no fat wallets.” Why? Here’s an undeniably good reason.
The risk of self-inflicted sciatica has increased in recent years with, for instance, sitting on a wallet for prolonged hours every day which can cause self-inflicted sciatica. (Source: Wikipedia)
If that doesn’t do it for you, try this one:
It’s not sexy. (Source: everybody)
There’s a few ways to go about this and don’t worry, you’ll have money left over to put back into your new wallet after you get it.
A money clip and a separate credit card holder

I think that clip is worth more than any amount of money you'll ever put in it.
Pros: You’re unmistakably carrying a money clip (immediate style points). It can also help reduce a lot of the bulk you carry around. For instance, you’re going out to the bar with the guys. You can leave your money clip in the glove compartment, all you’re going to need is your ID and a credit card.
Cons: You’ve reduced bulk, but you’re now also carrying a second item (which can get pretty annoying). Also, standing at a register trying to put your bills neatly back onto the clip makes you feel like the 5000 year old woman who still writes checks at the supermarket.
Cost: The ones shown here might be on the pricier range, but expect the combined cost to be between $20 and $80 (that’s a big range, I know).
A money clip and credit card holder COMBO!

I think this one has a fucking bottle opener too.
This [type] was my first slim wallet. I got some leather one at Office Depot for like 10 bucks. Great deal if you’re still trying to figure out what suits you.
Pros: You’re carrying one item instead of two.
Cons: Having a money clip slapped onto the back of your credit card holder isn’t particularly sexy. But at least it’s a small step in the right direction.
Cost: I wouldn’t go too fancy with this at first. Try it to see if you like it then upgrade to a nicer brand. $10-$50
Front pocket wallet

This is similar to what I use now, therefore it can do no wrong.
Pros: One item instead of two. The design is flush (no clunky metal shit on the back of your wallet). My personal favorite. Yes, that counts as a pro.
Cons: Not quite as much pizazz as the money clip. A little bit bulkier than the other options as it holds your cash too.
Cost: You can get a decent front pocket wallet like this for $20-$50.