I would really like AMD to release CPUs which can compete with intel's core M3, which can be used in SBCs or pocketable netbooks like these[1][2]. I feel there is a need gap in this space for a reputed manufacturer or a trusted enthusiast brand to get in.
Why would you want a pocketable Linux pc? one may ask; I'm tired of this always tracking smartphone cellular-apps cluster-X mess. My phone-call usage lifestyle is anyways on-demand(little to no incoming calls), so why not just use a USB GSM module on a pocket Linux pc when needed.
P.S. I'm aware of upcoming pure Linux smartphones, some with cellular-kill switch, I'm a vocal support of these platforms, but it's not available in my country and as I understand they are not ready for a daily driver.
You could probably run Linux on one of the GPD Win devices. (e.g. https://www.reddit.com/r/gpdwin/comments/glpokv/gpd_win_max_...)
Also, as an aside: rather than using a GSM module with a real SIM card that you'd have to pay monthly for, you could just subscribe to a VoIP service (I use https://voip.ms) and then connect to it with a softphone app to place and receive calls.
I pay $1/mo for a number, and $0.005/min for calling, and that's it. I have softphone apps for my PC, phone, and tablets, that are all connected to its same number, so I can answer calls "directly" through any of them, without one device having to route through another. (Also, as a side-benefit, I've set it up with has voicemail-to-MP3s-in-my-email, like Google Voice does. And configured it so that if people outside my whitelist call, they go directly to voicemail.)
Works especially well when combined with a phone that you set up as a "tablet" with a data-only plan. (This plan costs me $10/mo, in Canada, which is quite a feat if you know the Canadian cellular ISP market.)
Oh, and I've also written a SMS<->Slack bridge bot (https://github.com/tsutsu/smsforwarder), that I run as a Heroku free-tier app wired with webhooks to voip.ms's SMS API. SMSes to my VoIP number pop up in a Slack channel named after the peer's number in a special private Slack team I created; and messages I write into that channel are sent back to the peer number as SMSes. So all the same devices that have the softphone app, have Slack, and so can also interact with my SMSes in a shared manner as well.