The following is a partial list of heroic advantages I've come up with, some of which were converted to advanced skills.
Absolute Timing: You always know what time it is. A minor quirk, stolen from GURPS and priced at 5 hero points. This could be made an advanced skill, although that would just mean extra die rolls to determine if you know what time it is. So it's probably better as a heroic ability.
CPR Training: You are able to administer advanced CPR techniques. I originally made it an heroic advantage, costing only 2 points, to reflect the fact that there are advanced techniques that would not be available to the basic skill First Aid (especially those from archaic cultures, where CPR techniques would not even have been invented yet). But in a thread, I was convinced that this would be better handled as an advanced skill.
Expanded Intellect: Advanced concepts come easy to you. Must be taken at character creation. I don't see this as working as a skill; characters with Expanded Intellect can gain certain skills faster than normal.
Extraordinary Attractiveness: You are extraordinarily attractive. This does not make much sense as a legendary ability; a PC would have to take this at character creation. I don't see this working as an advanced skill, either, although I suppose a Cosmetics skill could be used to gain further advantage.
Martial Arts Training: Improved Damage: You can do extra damage with an unarmed attack. Axtxtq and I worked out a system where the normal Martial Arts skill can be used to determine extra damage, rather than just assume a +1D6. One of these days I should put it on the wiki.
Not the Face: You can force one reroll for hit location any time you are hit in the face by an attack. The second roll determines where the attack really hits. I suppose you could have a Direct Blow advanced skill to try to direct a blow away from a hit location you didn't want hit. I like the Not the Face heroic advantage, though. It's good for a guy called 'Face'.
Photographic Memory: You have true photographic memory. It is possible to define a Memory skill, but the point of this ability is to avoid having to roll Memory skill rolls. Also, it can only be taken at character creation.
Rapid Calculator: You can calculate mathematical problems very rapidly. This is another advantage that I stole from GURPS.
Two-Weapon Fighting: You are skilled with fighting with two weapons. This was adapted from the D&D feat of that name. I've decided it makes more sense to make a Two-Weapon Fighting skill specialization, but if you are not using skill specializations, what else can you do? Note: I've also decided to house rule the two weapon fighting rules to make two weapon fighting a lot harder for someone who does not have special training, in my campaign, in the form of the specialization.
Virtuous: You have a strong code of honor that sustains you in times of weakness. I came up with this advantage when I was trying to figure out how to determine whether a PC would be liable for getting a speeding ticket. Since defining this heroic advantage, I've decided that a Virtue advanced skill may work better, i.e., you can roll your Virtue if you have it and it would help you resist a spell or temptation, et cetera.
Wealthier: You can increase your wealth. This provides a way for a PC to play a very wealthy character, even one as rich as Bill Gates if the player is willing to spend the advantage/hero points, which could be within reach of a dedicated PC.
Anyway, the preceeding is intended to be examples of how I've thought of using heroic advantages. I think for Runequest Modern, I need them.
For Runequest Iron Kingdoms, I probably do not, although I did come up with a concept of metaphysical skills to allow for special special abilities (e.g. Rage or Uncanny Dodge). Metaphysical skills essentially become a kind of magic which can only be learned by someone who's mastered that skill. I'll probably put these into an upcoming thread soon.)
Hope this helps.