I bet you can imagine how many manufacturers send me products hoping that I will put them on TV. Well, here is one where I called MinWax and asked them to send me over some Wipe-On-Poly. I have fallen in love with this stuff.
It is simply a clear polyurethane finish, but formulated to not gum up when applied with a rag. The end result is the same polyurethane finish you get with a brush, but much thinner. You would have to put a lot of coats on to make it strong enough to walk on or use on a serious wear surface, but for non-wear surfaces it is great.
If you apply only one or two coats of it, it almost looks like an oil finish, but much more water resistant and washable. You can put on many coats and get the same durability as a brush on. Why would you want to work with so many coats, because it never drips or sags as it goes on so thin. When you are working with sculptured surfaces, or spindles, this can really make a difference. You can literally dab it into cracks and then wipe the excess right off. If you want to just put a very light refresher coat over a regular poly finish, it will pick up those little scratches and smooth the finish out with much less work that a brush coat that you have to be so careful with.
If you like working with oil but you need a polyurethane finish, try Wipe-On-Poly from Minwax.
If you have a very light hot cup mark in a table, first test to see if it is a lacquer finish that can be totally repaired with "furnisher refinisher" -- but if it is a plastic finish, take "00" steel wool wetted with Wipe-On-Poly and very gently use the steel wool to remove just a fraction of the discoloured finish. Wipe that clean with a cloth and let dry, then apply more coats of the wipe-on poly with the rag to build the finish back up. It doesn't always work, but it usually does a fair to fantastic job.
Now I do have one complaint about the product. Because I tend to just dump it from the can onto a clean rag for small jobs, I get some on the outside of the spout. Then when I close the can, that freezes into a nightmare to open because of the child-proof gadget on the lid. I have learned to very carefully wipe off the threads on the can before putting the lid back on, and occasionally clean them off with steel wool to get the lid on and off easily again.