I am a teacher/rabbi in Potomac Md and have been thinking about the PostIt note issue. I searched Google and found your response. I believe that if ones looks in Shemirat Shabbat C’Hilkhata chapter 9 notes 19 and 55 one you may draw a different conclusion. I would be happy to share a dialogue/my notes with you about this issue.
Gluing papers one to another is a Torah prohibition a Toladah (derivative) of Tofer (sewing). If the gluing is not permanent, it not a problem of Tofer on Shabbat. Non-permanent for that matter is till the end of Shabbat but if planned to stay longer – it stops being non-permanent. (Shulchan Aruch OC 340, 14; MB ibid 45; MB 314, 44) The Shmirat Shabbat Kehilchata (9, note 19) explains the notion to mean that only if it forms one body by gluing it, but not for instance if only the edge of the bag is glued like in plastic wrappers. The Shmirat Shabbat brings more (in note 77) that only gluing two pieces of paper together it will be Tofer but if gluing a paper to a hard solid thing i.e. a sticker to a bottle it will not be prohibited as they don’t join together the same way as two papers. Therefore one should distinguish the way post-it sticker is used. If it is posted on paper for a long period – it should not be done on Shabbat (as I wrote in the previous Responsa) If it will be use only temporarily for that Shabbat or on a solid surface (table, glass) it seems to be permitted. In Orchot Shabbat (p. 345) he brings from Rav Elyashiv that he permitted to seal the windows during the Gulf war on Shabbat but only the first layer – the tape to the window but not the second layer – tape to tape. He concludes that one might not learn from that as it was a war time and maybe that in the first place it's better to avoid all cases of gluing.