Apart from my project work and in my "spare time", I try to work on various other issues within different fields of linguistics:

Graphematics / Orthography.  I did a lot of coursework in the history of German spelling. And from my attempts to learn various languages (like French, Russian, Hungarian, and modern Greek) as well as from teaching Bahasa Indonesia I know how difficult it can be (made) to relate sounds to letters and vice versa.
The Indonesian orthography is called "perfectioned spelling", but a closer look reveals that even this system bears some difficulties and flaws in it.  Currently, I am trying to figure out what - if anything - makes a "good" or even "perfect" orthography in general and for a given language like German or Indonesian. In addition to that I want to find out what level of "perfection" the "perfected orthography" of Indonesian and regional languages of the archipelag really have and whether "perfection" could be achieved at all.
Furthermore, on a more abstract level, I want to investigate which criteria should be met to make a spelling easy to learn and use both for native speakers and learners of a foreign language. I hope to cooperate with a few colleagues here at the MPI and at various Universities on this issue, e.g. Søren Wichmann (MPI EVA) and Viola Voß (Münster).
The typology of writing systems and universals of writing are also part of my interest here. Together with Viola Voß, I taught a Spring School class on the topic. In mid-2006, I also gave a lecture on orthography development at a regional DoBeS training workshop in Ubud (Bali, Indonesia) and in fall 2006, I gave two lectures at Universitas Negeri Surabaya (Java, Indonesia) on comparative orthography.

Pragmatics. I am also interested in (linguistic) politeness, speech styles, and avoidance systems. Furthermore, I like discussing issues of cultural contact and intercultural competence (with particular reference to "politeness" or "communicative adequacy")  Due to limited time, however, I am not engaging in any substantial research here. Together with Corinna Handschuh (Düsseldorf/Leipzig) I wrote a brief paper on applying optimality theory to decribe politeness strategies.

Sociolinguistics. Language contact and related issues are definitely one of my favourite subjects in linguistics. Since my dissertation is about borrowing, I am spending a lot of time in this discipline. Maybe the one or the other written spin-off will evolve from that work.
Although (or: especially because) I am not involved in language documentation myself, I wish to promote the documentation of endangered languages and the urgency of linguistic fieldwork.
The notion of endangered subsystems (writing system, numerals, onomastics, speech registers) is fairly new in this list of interests. So far, I have not done extensive research in that field, but I am thinking about the one or the other paper on this.
Together with Tyko Dirksmeyer, I edited a collection of students' papers on language death. The book was published in late 2005 with Weissensee Verlag (Berlin).

Syntax. My M.A. thesis (2002) was about verbal diatheses in Indonesian, and from time to time I will probably draw upon this background for a paper or a talk. Apart from that, I feel not too attracted by this field.

Typology. Taking up an incentive by Larry Hyman and inspired by a database initiated by Frans Plank, I am planning to do some work on language particulars (rarissima et rara) as opposed to language universals (universalia et frequentalia). Universals have been studied thoroughly for the last four decades, allowing fundamental insight on the principles and general properties of human languages. At the other end of the scale, features and properties found only in one or very few languages (call them rara or quirks, if you like) tell us almost as much about the capacities and limits of human language(s) and challenge our concepts of typological generalizations. A cooperation of several typologists and fieldworkers would be more than desireable. Currently, Orin Gensler, David Gil, and Michael Cysouw (all MPI EVA) are involved in this project. We hosted a conference on this in March 2006.