Although it raises some sticky modern ethical dilemmas for some people, and is guaranteed to start a fight in most groups, cursing can be found in all (to my knowledge) ancient cultures. Norse cursing has its own distinct flavor that makes for an interesting subject to look into.
Possibly one of the most well known types of Norse curses, at least within Heathen groups, is the nidstang. A Nidstang, or Nithstong (scorn-post) is a 9 foot long pole carved with runes that curse a specific person and topped with a severed horse's head or skull (Pennick, 1993). The basic idea of such a pole was to disturb or enrage the landvaettir in such a way that they turned the luck of the target of the curse bad (Pennick, 1993). Nidstangs could also be used to desecrate an area, in which case they were called alfreka, meaning to drive away the elves, with the understanding that to drive away the landspirits was to make the area spiritually impotent (Pennick, 1993). Nidstangs were also combined with curse-runes, where certain runes such as thurisaz were carved a specific number of times in order to negatively effect the targeted person. In Egil's saga, Egil places a curse upon the king and queen who have made him an outlaw by erecting a nidstang and reciting a verbal curse to deny the spirits of the land rest until they force the king and queen out of the country.
Modern digital nidstangs containing a written curse exist online and have been used for such diverse purposes as cursing negative groups that have co-opted heathen symbols to cursing the perpetrators of the 9/11 terrorist attacks. Such a digital curse would work in a different fashion from the traditional poles, unless the caster believes there are digital or virtual wights that can effect the person and aims at turning them against the target. I would say that this type of modern nidstang is aimed more at making a bold public statement or damaging the target's reputation.
Part of the ritual associated with the nidstang includes spoken or chanted curses and we also see these separately, sometimes used with the invocation of runes. In the Curse of Busla, for example, we see both types as Busla attempts to use witchcraft to save her condemned son by cursing the king, after confronting him as he slept. First she chants a long curse, which includes the verse:
"Shall trolls and elves and tricking witches,
shall dwarfs and etins burn down
shall thurses hate thee and horses ride thee,
shall all straws
stick thee, all
storms stun thee:
and woe worth thee but my will thou doest" (Hollander, 1936)
When the king is still not willing to fully pardon her son, she continues with the final and most powerful verse:
"Come here six fellows: say thou their names:
I shall show them to thee
But thou get them guessed as good me seemeth,
ravening hounds rive thee to pieces,
and thy soul sink to hell-fire!” (Hollander, 1936).
after reciting the curse she draws specific runes in a pattern. Only after this does the king relent and Busla removes the curse she has just layed on him.
Similar to this we see another type of curse that was spoken but relied on verbally invoking specific runes. One version of this type of curse that I find particularly entertaining to study is the fretrunir, or farting curse. A father and son in Iceland were executed in 1656 after being convicted of using this curse against a pastor and a local girl in what is known as the Kirkjubol witch trial. Part of the chant that they used was said to be:
“which are to afflict your belly with great shitting and shooting pains, and all these may afflict your belly with very great farting. May your bones split asunder, may your guts burst, may your farting never stop, neither day nor night. May you become as weak as the fiend, Loki, who was snared by all the gods.” (http://www.worldsstrangest.com/mental-floss/the-mystical-farting-runes-of-iceland/)
Clearly the intent is not only to humiliate the person with excessive gas but also to cause serious health problems relating to the stomach, intestines, and bowels. Another version from the Galdrbok includes the runes used and invokes an array of Heathen and Christian Powers, clearly with the same intent as the Kirkjubol example:
"I write you eight áss-runes, nine naudh-runes, thirteen thurs-runes — that they will plague thy belly with bad shit and gas, and all of these will plague thy belly with great farting. May it loosen thee from thy place and burst thy guts; may thy farting never stop, neither day or night; thou wilt be as weak as the fiend Loki, who was bound by all the gods; in thy mightiest name Lord, God, Spirit, Shaper, Odhinn, Thorr, Saviour, Frey, Freyja, Oper, Satan, Beezlebub, helpers, mighty god, warding with the companions of Oteos, Mors, Notke, Vitales." (http://witchofforestgrove.com/2010/11/17/the-ethics-of-malevolence/)
There are also examples of rune staves used for cursing, generally by carving the runic symbol on an object such as a piece of wood or bone and then placing it in the path of the target. Several of these types of rune staves can be seen in the Museum of Icelandic Sorcery and Witchcraft such as the killing rune which is intended to kill livestock belonging to the target. Those who study runes in modern practice also have found that certain runes used on their own can be effective curses, generally aimed at disrupting a person's luck or negatively impacting things around them or their health.
Pennick, N., (1993). Runic Magic: the history and practice of ancient runic traditions
Hollander, L. (1936) Old Norse Poems