Looking through the school of enchantment on the SRD, I find the lack of helpful spells slightly disconcerning. Where are the spells that bolster the mind, make it stronger and more flexible? While thinking about that I came up with a pair of focal and series magic items. Focal items requires a spell to function and series items mean more than one of them results in more powerful effects. The former is found in Dragon 111 and the later in Dragon 213 (there is also 3.5 versions of the former in Green Ronin's Advanced Gamemaster's Guide and the latter in Distant Horizon's The Practical Enchanter).

There are many versions of Magical Menhirs, some used before battle, some used to crush the will of many but most are meant to keep people together and make them stronger as a group. The Community Menhir is a stone that helps reinforce social ties. They are used every so often, once or twice per season, by having a massive party around them (anything from a quite time of reflection and conversation to an orgy). All the people who participate gain a weak form of empathy, a strong mental shield and the community as a whole becomes more bountiful. The empathy is used to help root out problems within the community, and hopefully those that can be solved right there and then. More people and more menhirs means more powerful effects. A single stone gives +2 to saves versus negative mental attacks, psionic and magic, for a month. Every stone thereafter adds an additional +1, to a maximum of +12. If there are more than five stones, the duration increases to three months and more than ten stones increases that to six months. The community effect is similar to 3e Plant Growth, but affects crafting as well as agriculture (i.e. adds 30% to productivity). To activate a Community Menhir, there has to be at least 40 people within 100' of it and a divine spell of 2nd level or arcane spell of 5th level cast into the stone (it has no other effect). It will affect automatically everyone within range, even those who are unwilling.

The Helm of Many Minds divides the wearer's mind into nine parts- one for each alignment. The original mind is dominate and there is no overt fighting between them. What this does is allow the wearer to understand the position of anyone of their race. In d20, this results in a +20 to Diplomacy checks. In Labyrinth Lord, the result of an encounter check is always a 2 (pages 47 and 52). When interacting with other races that are not blood enemies, the result is a +10 to Diplomacy and d3+1 roll in LL. If there are more than one Helms of Many Minds worn by allied individuals within 30', the Helms set up a telepathic web where all the minds communicate. This gives the wearers access to http://en.wikipedia.org/wiki/Wisdom_of_the_crowd This gives a bonus to all Intelligence, Wisdom and Charisma based skill checks at a rate of +2 per helm after the first. If any one wearer has at least one rank in a skill, then all of them have equal access to that skill. I would mention some bonus in LL but it has no skill system. Still, there should be some significant bonus from using the telepathic web (spell research and magic item creation?). What it doesn't do in any edition is allow the transfer of spells or psionic powers.