Some gyms have automated belay equipment. It's a bit clunky and not everyone likes using them but they do exist and do work.
I have always climbed with a partner but we have also included other people into our group who needed a belay partner. I would think that it's definitely possible to find a partner for the day but it is easier to just bring your own.
There is also bouldering, which doesn't require a partner but doesn't go as high either.
Bouldering is a better way to do deliberate practice if you want to actually improve your skills - you can practice a particular movement again and again until it's right, with minimal overhead between retries. But you might prefer a wall from a fun PoV.
What can I purchase with $100 that will be the best thing I can buy to make my life better?
I've decided to budget some regular money to improving my life each month. I'd like to start with low hanging fruit for obvious reasons - but when I sat down to think of improvements, I found myself thinking of the same old things I'd already been planning to do anyway... and I'd like out of that rut.
Constraints/more info:
Background:
This is a question I recently posed to my local Less Wrong group and we came up with a few good ideas, so I thought I'd share the discussion with the wider community and see what we can come up with. I'll add the list we came up with later on in the comments...
It'd be great to have a repository of low-hanging fruit for things that can be solved with (relatively affordable) amounts of money. I'd personally like to go through the list - look at candidates that sound like they'd be really useful to me and then make a prioritised list of what to work on first.