I need a piece of wood to place above a window, to which I'm going to attach a curtain rail. I'd like it to match an existing piece of wood above another window, which has quarter-round edges all around. What are my options, given that I don't own a router?
I would expect that most retail outlets do not offer to run wood through a shaper or do router work. What you really want to look for is a crafts-person that has the tools to do this for you.
If your intent is to avoid having to pay someone to do a project like this then take the opportunity to figure out how you can do it yourself. There are a number of options that you can investigate:
You could elect to purchase a router and bit that can cut the round over edge on the wood piece. This approach may not actually cost too much more than outright paying a crafts-person.
There are tool rental businesses that allow you to pay a small fee to use a tool for a day or half day. This is usually a fraction of the cost of buying a quality tool of your own.
There are lower cost hand tools that can be used to create a rounded over edge on a board. A nice sharp hand plane and a sand paper block can do the trick with a little time investment.
You can ask around. You may very well find a friend or colleague that has the tools and would be more than willing to do the routing on your board. You may find it appropriate to offer a meal out or a visit to the pub as a return favor.
One possibility would be to get a piece of quarter-round and glue or otherwise affix it to the edges of a flat-sided piece of wood matching the non-rounded dimensions that you need. The corners will need to be dealt with, and could be cut with a lot of work with a random orbital sander.
Another option is to shape the quarter-round by hand as suggested above. I have actually had good success using the aforemention random orbital sander to do just that, depending on how big the piece is and how perfect it needs to be (ie. how far away will people be standing when they look at it, and what color will it be in comparison with its background).