I should qualify that I'm now attending conferences as a participant and no longer covering them as a journalist. But even as a attendee, I used to bring a notebook and camera to capture copious notes. I put business cards in my badge holder and dutifully sent out networking emails the next day. I lugged a tote bag full of vendor information and marketing material.
Now, I just bring a phone and a large purse.
Most panel sessions have slides, video and product information posted online, so there's no need to take detailed notes. I use ColorNote for any residual notes. When I meet someone and we want to connect, we do so right away on LinkedIn. Or, I can follow them on Twitter. Book recommendations that I get, I bookmark on Goodreads. Action items go in my Google Keep to-do list, which syncs across devices. Even vendor schwag has gotten smaller, either edible on the spot (that part hasn't changed!) or placed on USB sticks.
The obvious benefit is that I no longer carry lots of stuff. Another benefit is that I'm prioritizing and acting on the information while I'm consuming it rather than waiting for later. How many post-conference actions have I forgotten to do once I'm back at work?
The obvious drawback is that the constant multitasking prevents me from absorbing some amount of information. Plus, it must be a bummer for presenters to see most of the audience on their phones. Are they bored and on Snapchat? Or are they filtering and processing the information? Hard to know.