Early adopters have no choice but to buy Apple's $79 USB-C Digital AV Multiport Adapter, because right now, it's the only game in town. After you plug it into the MacBook's lone port, you'll have a USB-C charging port, a USB 3.1 port and an HDMI port with up to UltraHD output (Apple has a similar cable with VGA). Let's be real here: the MacBook is pretty expensive starting at $1,299, and this peripheral should be included. If you want to pay less and don't mind swapping cables, you can settle for Apple's $19 USB-C to USB 3.1 cable that will at least let you plug in, say, a standard USB key. If you need a USB-C to USB Micro-B adapter instead, Belkin has one coming soon for $30.
What about storage? As mentioned, transferring files from a regular USB key or drive is a pretty basic task that you just can't do on a MacBook. Fortunately, SanDisk has a 32GB, $49 dual USB drive coming in June that you can plug into both Type-C and standard USB ports. If you need more space, LaCie's Porsche Design USB-C drive (with a USB 3.0 adapter cable) arrives this summer in 500, 1TB and 2TB capacities. There's no pricing yet, but Lacie has a similar USB 3.0-only device starting at $75.
If you're willing to punt on Kickstarter, a company called InfiniteUSB has USB-C cables that sport a male connector and female pass-through socket, letting you stack as many as you want. The design is based on the company's standard USB stacked cable, which has been around since 2010. The cables come in MicroUSB, Lightning or female USB flavors and start at $18 each. They're compact and fold magnetically, letting you travel light and add connectivity as needed -- but you can't use them and charge your MacBook at the same time. The company has exceeded its $10,000 goal many times over with nearly $200,000 pledged.
Other Kickstarter options include the $19 BeeKeeper USB-C to USB 3.0 adapter, which lets you keep a standard USB cable on your MacBook, even for charging. Finally, there's the HydraDock hub (above). From a single USB-C connection, it gives you 11 ports, including a 3.5mm stereo headphone port, a gigabit ethernet port, an SDXC card slot, a mini DisplayPort, one HDMI output (1080p max), 4 USB 3.0 ports and 2 USB-C ports. It looks versatile enough to solve all your connectivity issues, but it's still halfway to its funding goal. And like all things Kickstarter, there's a chance it'll never see the light of day.
Update: The post originally said that the MacBook price started at $1,149, but the actual starting price is $1,299. Our apologies for any confusion.