Regular Expressions -- Not the irregular ones your professors warned you about!
In a nut shell, a regular expression is a pattern that describes a section of text. If you haven't learned about regular expressions then I highly recommend you take the tutorial at Regular-Expressions.info. When I'm testing my regular expressions I use their Regular Expression Tester.

Tools for getting into the regex work.
I made a VBA module for performing regex work. I also reference a Word document by D. Brett as it contains information on binding the RegExp Object and has the pattern table with descriptions. Very helpful.

Red, Green, Blue to Long Number translator.
This VBA module will accept a RGB value and return a Long value. I can't remember exactly why I made this except that I needed a color from one location to paint a Shape the same color. Eh.

Capture a user's Windows Login name. -- Just don't let it escape out the door.
Some of the applications I built would have special capabilities for specific users. To easily figure out who's running the program, simply grab their user login name.

Quick Query/Pivot Information Add-in.
This query add-in places a menu item in the right mouse-click menu. If the query is a Query table then the menu item will be "Query Information" or if it's a Pivot table then it will display "Pivot Information".

Selecting the menu item will display a user form with the specific information. If you change the text in a box and double-click the text box label, it will change the value for that particular item of the query.

Text box titles in bold are the parts of the query the add-in found and are changeable. For example, you could change the Command text in the box then double-click the Command text: label to make the change to the underlying query. This won't always work for all underlying queries, for example, queries that point to an ODBC data source that you don't have a defintion for. Even still, this is a good way to simply see what's going on inside a particular query.

Go to sleep my sweet little baby.
This tiny executable is something I created in Thompson's AWK back in my Intel days and allows a batch file -- or any file that calls it for that matter -- to pause for a certain length of time. In a batch file you'd simply call it (with the proper file path if necessary) with a space after it and a number. The number represents the number of seconds you want to wait before continuing. For example:

Nothing spectaculer, I know, but it sure was helpful when I was automating reports and needed to insure the first process completed before starting the next without having to do any special coding.

Converting columns to values and back again.
Here are two VBA functions that I've used several times while making custom reports for customers. This function will convert a value to a column. Simply pass it a number and it will return a letter that designates the appropriate column. For example,

sColumn will equal the letter "E". Likewise, passing it the number 27 will return "AA". Neat, huh?

Conversly, we can convert a column to a value. Simply pass it a string that is the column header and it will return an integer. For example,

iColumn will equal 5. Similarly, passing it "AA" will return 27.

Two column VLOOKUP.
If you do a lot of reporting in Excel then you likely use the VLOOKUP function. But how many times have you wished you could use two values to determine the lookup? Well I have and I found a neat little function by Andy Wiggins called VLOOKUP2. This is the syntax: VLOOKUP2(lookup_value1, lookup_value2, table_array, col_index_num). Instructions are in the .bas module but it's pretty darn simple; instead of ONE value used for the lookup you now have TWO. Andy, I salute you!