It may be because I grew up with four sisters but I think men are notoriously hard to buy for; there are only so many books and CDs you can buy before it looks like you're not even trying...
So, we've put together a few ideas to get you going, but, please, offer up your suggestions in the comments. I need all the help I can get!
For the Beer Man
Sometimes drinking beer is just not enough. Brooklyn Brew Shop's Beer Making Kits include everything he needs to get started, including a glass fermenter so he doesn't have to mess up the bathtub. And even if he's not making his own home brew, Beer Savers, (which come in six different colors) act as "cap charms" and tell other folks, "Hands off! This one is mine."
For the Man About Town
Of course he's going to need to transport his new home brew around town so all of his friends can grab a taste! The Bent Basket is a wooden basket that skips the bungee cords in favor of a cool strap that will hold down just about anything he can throw on it. Or Public Bikes, which has created a line of urban bikes that are to die for, offers a removable wire basket that easily clips on to your back rack (my husband takes ours into the grocery store, good man that he is).
For His Casual Weekends
You really can't go wrong with a t-shirt, or in the case of Threadless, twelve t-shirts. They offer a T-shirt-of-the-month-style club, where each month an exclusive design will show up on his steps. Print Brigade's "I love my bike" t-shirt would pair nicely with their soon-to-be-released I Love My Bike book. Or Campfire Goods line of City tees let him show off his city and what they're most know for (Denver: City of Peaks, Atlanta: City of Coke, Seattle: City of Nerds...you get the idea).
For the Tech-y Guy
Taking great photos shouldn't be hindered by carrying around a heavy camera. Photojojo's magnetic lenses (fish-eye and wide-angle/macro) snap onto any camera phone, letting him take pro-quality photos with just his phone. Add to it, Camerabag, a handy little app that lets him add custom filters to photos so he can make them look like Polaroids, age them, or brighten them up, and you might just have some prints for your wall...
For the Wine Guy
Have a cork from a special bottle of wine the two of you shared? Corkeeper lets you memorialize the memory with their photo Corkeeper frame (it also leaves you space on the back to write a meaningful note). A Date with Wine wine stopper makes sure he never drinks wine past its open date with a twistable date ring that lets him mark the date the wine was opened.
Check out our Mother-of-the-Groom guide and Bride's Guide, as well!