I'm doubtful that anybody but me will find these ideas useful, but I will share them anyway - just in case.
I'm inspired somewhat by the TMG refugees who are looking at RM, The TMG refugees are looking for a way to accomodate TMG's flags in RM. I realize that creating user defined facts in RM to simulate TMG's flags is not really adequate for many TMG users, but I think the idea is really interesting anyway. I have already been doing a similar thing by placing something akin to flags into RM's Reference Number field since I wasn't using the Reference Number field for reference numbers. But I have embarked on a project to move these "something akin to flags" things to user defined facts, and I'm extremely happy with the results so far.
One of the ways I'm using RM's user defined facts as "something akin to flags" is to create sort of a combined ToDo list and Research Log. Why would I do such a crazy thing when RM already has a perfectly servicible ToDo list facility and a perfectly servicible Research Log facility? Well, for reasons I don't understand I simply don't like RM's ToDo list. I do sort of like RM's Research Log facility and I have warmed up to it. Unfortunately, I find that the labels that the Research Log has for the boxes where I enter my data not to my liking. Laura suggests simply ignoring those labels and pretending they mean what I want them to mean. I can do that, but it's hard for me - being a very literal person.
But that is not really why I'm inventing my own ToDo list system and Research Log system within RM. The overarching reason for inventing my own ToDo list system and Research Log system by using RM's user defined facts is that it gives me full integration with the rest RM and it gives me full exportability with any other genealogy software. For example, I can search my new ToDo list and Research log, including color coding and creating Named Groups based on my ToDo lists and Research Log. I can place the Description field of my user defined facts into a column in People View. I can use the Note field of my ToDo lists and Research Log to store any information I want in any format I want, without any restrictions on what I call things or how they are formatted. It then becomes quite trivial to make very useful reports about my ToDo lists and Research Logs with RM's custom report facility. It is also quite trivial to make very useful reports using SQLite, but I find that it's not necessary to do so because it's so powerful to do the work in People View instead.
So let's give a couple of examples. I have a very long term project to gather every single courthouse marriage record that I can find for every marriage in my database. To that end, I have created a user defined fact called *flag_marriage. All of these user defined facts that I'm talking about are called *flag_something, where "something" is "marriage" or "obit" or "death_certificate" or something like that. This naming convention places my user defined facts all together and places them at the beginning of my fact list. If I'm working on one of them a great deal, I will rename it temporarily as **flag_something to place the active one at the very beginning of the list to make it easy to select. I will later rename it back to only having only a single asterisk. For all my user defined facts of this form, I'm enabling the date field and the description field (but not the place field), and I'm including it only in GEDCOM export (not in publish online, narrative reports, etc.)
Back to the example my courthouse marriage record project, all I have to do to work on my marriage record project is to add my *flag_marriage fact as a column in People View. Individuals for which the *flag_marriage fact is blank or null are the people for whom I don't have a courthouse marriage record. I use the *flag_marriage Description field as a ToDo list, and I use the *flag_marriage Note as a Research Log. For example, on 30 Oct 2014, I e-mailed the Carbon County, Pennsylvania courthouse to request a marriage record from 1946. I added a *flag_marriage event with 30 Oct 2014 as the event date (which I'm using as the most recent activity date, there can be more date details in Note field), with "emailed Carbon County courthouse on 30 Oct 2014" as the Description field, and with a copy of my email in the Note field. They responded promptly with instructions on ordering the record. So I added their email to the note, changed the event date to 11/1/2014, changed to the description field to "mailed a check to Carbon County courthouse on 11/1/2014", and mailed them a check. When I get the image of the courthouse record, I'll scan it in and process it as normal. I'll change the event date of the *flag_marriage date to the current date, and change the description field to "ok" or "done" or something like that. It's all very simple. It's all very visible. It's all very easy to manage. And my user defined *flag_marriage fact should export just fine to most any genealogy program, including its date, description, and note.
It turns out to be really useful to place a Named Group into People View rather than my entire database. This is especially true with my user defined facts that are serving as a ToDo list and as a Research Log.
Here are some examples of other user defined facts that I have defined so far as ToDo lists and Research Logs: *flag_grave (my project to gather photographs and GPS coordinates of all grave markers), *flag_obit (my project to gather all obits where such obits exist), *flag_paragraph (my project to be sure user every person's data prints with appropriate white space in narrative report - no data has to be collected, but having gotten a person's white space correct in a report I want to have some way to know that I don't have to look at them again), and *flag_city_directory (my project to gather all city directory entries where such city directory entries exist). I expect to be adding many, many more of these special user defined facts.