GSAK supports drag and drop.
Opening Files by Dragging
When you drag a GPX or LOC file onto the database area GSAK displays the Load GPX/LOC File dialog box, with the name of the file you dropped already entered in the file name field. GSAK also supports drag and drop for ZIP files. If you drag a ZIP file here, GSAK uses the first file found inside the ZIP file. This feature allows you to just drag and drop the ZIP file sent via email from www.geocaching.com.
You can also drag files onto the GSAK desktop icon. This executes GSAK (if not already active) and shows the Load GPX/LOC File dialog box, as above.
You can drag files from Windows Explorer and most email clients (Microsoft Outlook is one noticeable exception, but Microsoft Outlook Express works OK).
Dragging Columns on the Main GSAK Screen
Depending on your screen resolution, you may not be able to see all columns in the display. Use the Horizontal Scroll Bar to scroll the grid to the right or left. Alternatively, if you are dissatisfied with the default layout, or if there are columns that you rarely use, you can reorder the columns by dragging the column heading to the new location.
Dragging waypoints for export
GSAK also supports Drag & Drop for exporting waypoints. This makes it especially easy to export just a single waypoint.
Hold down the left mouse button on the required waypoint then start moving the mouse. You will notice the cursor will change and the tool bar will alter so only the buttons that support "dropping" will be visible. Now just drag the mouse over the required tool button and then "drop" (release the mouse button) to action the export.
When you drag and drop a waypoint in this manner, the export will run immediately without any dialog prompts using the last active settings for that dialog.
You effectively have two other options when you perform the drop by holding down the SHIFT and/or the CTRL key
Shift - Holding down the shift key before "dropping" will export your current sub set (filter), rather than just the current waypoint. Note: this export also runs transparently in "macro mode". That is, your last active settings for the corresponding export are used and there are no message dialogs to hold you up.
Ctrl - If you would prefer the traditional export dialog to show so you can change settings etc, then hold down the CTRL key. This takes the "drop" out of "macro mode" and you get all the normal prompts and messages.
Yes, you can hold down both the Ctrl and Shift keys when doing the drop. However, I see little point because the combined behaviour of these actions would be exactly the same as just clicking on the tool bar button in the first place which I would think would be easier.
If you have several formats you export to, make sure you customize your tool bar to show these buttons so you can use drag and drop with them.