I am curious to know if it is possible to dissolve only the selected features in a layer in QGIS. In ArcGIS this is the default behaviour (which was actually someone annoying most of the time), but it can be useful to avoid having to export all the features to be dissolved to a new file, dissolving them, and then pasting them back into the original. Is this possible in QGIS? I do not see it in the Vector > Geoprocessing Tools > Dissolve dialog.