

I don’t on the couch, but occasionally I do on my bed. Not stuff like first person shooters, but less-frentic mouse based stuff.
I have a USB trackball and a USB trackpad, and I’ll use one of those.
I am not as accurate or quick as I am with a mouse with either of those, but both work fine without a rigid, level surface.
EDIT: My problem for use on a bed isn’t really the mouse, but the keyboard. I have used a split ergo keyboard, with one half on each side, but even that isn’t amazing. I don’t have a reasonable way to do much typing if you’re not sitting up.



























I generally don’t think that old PCs are that useful. I don’t usually make much use of mine. That said:
If you don’t have a server and need one that doesn’t require latest-and-greatest hardware to do something, I think that that’s probably a good choice. You already know the hardware. All kinds of things that one might do, fileserving, home automation, whatever. I’ll also mention some less-obvious options below.
Reserve PC. If you have the space to store it and only have one PC, having a second for if something goes horribly wrong on the first can be helpful. Not so bad these days, since most people have a smartphone, and it’s not so hard to find a computer.
Alternate OS machine. If you want to maybe use another OS on bare metal, another machine can be a way to do that.
Print server/3D print server/pen plotter server. A lot of newer printers have their own print server built in, but not all do. I was looking at pen plotters from Bantam Tools the other day. They don’t. Especially with 3D printing and pen plotting, elaborate tasks may take some hours. You don’t want to have to reboot your attached computer, and you might want to put noisy hardware in another room from your main PC.
Security camera server. Detect motion, log images, maybe notify you. Don’t want to have the load on your main PC.
Whole-house music PC. Maybe run something like
mpd, which has good support for remote control Hook it up to your fancy sound system.Guest PC. Most people do have a smartphone or laptop these days, but it might be useful to have one available.
Router. I’d probably get dedicated hardware for this and run OpenWRT, but you can use a PC for it, if you equip it with suitable hardware.